Thrombin inhibitors

ABSTRACT

Compounds of the invention are useful in inhibiting thrombin and associated thrombotic occlusions having the following structure: or a pharmaceutically acceptable salt thereof, wherein R2 is R3 is selected from the group consisting of 1) hydrogen, 2) halogen, 3) C 1-4 alkyl, 4) C 3-7 cycloalkyl, 5) CF3, 6) OCF3, 7) C 1-4 alkoxy, and 8) cyano; and R12 is a 5-membered heteroaryl ring having 2, 3, or 4 heteroatoms, provided that at least 1 heteroatom is N, and at most 1 of the heteroatoms is S, said ring being unsubstituted or substituted, at any one ring atom, with CH3.

BACKGROUND OF THE INVENTION

[0001] Thrombin is a serine protease present in blood plasma in the formof a precursor, prothrombin. Thrombin plays a central role in themechanism of blood coagulation by converting the solution plasmaprotein, fibrinogen, into insoluble fibrin.

[0002] Edwards et al., J. Amer. Chem. Soc., (1992) vol. 114, pp.1854-63, describes peptidyl a-ketobenzoxazoles which are reversibleinhibitors of the serine proteases human leukocyte elastase and porcinepancreatic elastase.

[0003] European Publication 363 284 describes analogs of peptidasesubstrates in which the nitrogen atom of the scissile amide group of thesubstrate peptide has been replaced by hydrogen or a substitutedcarbonyl moiety.

[0004] Australian Publication 86245677 also describes peptidaseinhibitors having an activated electrophilic ketone moiety such asfluoromethylene ketone or aketo carboxyl derivatives.

[0005] R. J. Brown et al., J. Med. Chem., Vol. 37, pages 1259-1261(1994) describes orally active, non-peptidic inhibitors of humanleukocyte elastase which contain trifluoromethylketone and pyridinonemoieties.

[0006] H. Mack et al., J. Enzyme Inhibition, Vol. 9, pages 73-86 (1995)describes rigid amidino-phenylalanine thrombin inhibitors which containa pyridinone moiety as a central core structure.

[0007] The present invention concerns pyridinone- and pyrazinone-basedcompounds having heterobiaryl substitutents.

SUMMARY OF THE INVENTION

[0008] The invention includes compounds for inhibiting loss of bloodplatelets, inhibiting formation of blood platelet aggregates, inhibitingformation of fibrin, inhibiting thrombus formation, and inhibitingembolus formation in a mammal, comprising a compound of the invention ina pharmaceutically acceptable carrier. These compounds may optionallyinclude anticoagulants, antiplatelet agents, and thrombolytic agents.The compounds can be added to blood, blood products, or mammalian organsin order to effect the desired inhibitions.

[0009] The invention also includes a compound for preventing or treatingunstable angina, refractory angina, myocardial infarction, transientischemic attacks, atrial fibrillation, thrombotic stroke, embolicstroke, deep vein thrombosis, disseminated intravascular coagulation,ocular build up of fibrin, and reocclusion or restenosis of recanalizedvessels, in a mammal, comprising a compound of the invention in apharmaceutically acceptable carrier. These compounds may optionallyinclude anticoagulants, antiplatelet agents, and thrombolytic agents.

[0010] The invention also includes a method for reducing thethrombogenicity of a surface in a mammal by attaching to the surface,either covalently or noncovalently, a compound of the invention.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

[0011] Compounds of the invention are useful as thrombin inhibitors andhave therapeutic value in for example, preventing coronary arterydisease. The invention includes compounds having the followingstructure:

[0012] and pharmaceutically acceptable salts thereof, wherein

[0013] A is

[0014] 1) a 6-membered non-heterocyclic unsaturated ring system,unsubstituted, monosubstituted, disubstituted, or trisubstituted, sameor different, with C₁₋₄ alkyl,

[0015] 2) a 6-membered heterocyclic unsaturated or saturated ring systemwherein 1 ring atom is selected from the group of heteroatoms consistingof N, O and S, wherein the ring carbons are unsubstituted,monosubstituted, disubstituted, or trisubstituted, same or different,with C₁₋₄ alkyl,

[0016] where R⁹ is hydrogen or C₁₋₈alkyl, or

[0017] 4) —C₃₋₈ cycloalkyl;

[0018] Z is —(CH₂)₂₋₄—, —CF₂(CH₂)₁₋₃—, —(CH₂)₁₋₃SO₂—,—(CH₂)₁₋₂NH(CH₂)₁₋₄—, or —CH₂CH(R⁴)—, where R⁴ is —(CH₂)₁₋₂N(R⁵R⁶), andR⁵ and R⁶, same or different, are selected from the group consisting ofhydrogen and C₁₋₄alkyl;

[0019] X is CH or N;

[0020] R¹ is hydrogen, halogen, or C₁₋₄alkyl;

[0021] R² is

[0022] R³ is selected from the group consisting of

[0023] 1) hydrogen,

[0024] 2) halogen,

[0025] 3) C₁₋₄ alkyl,

[0026] 4) C₃₋₇ cycloalkyl,

[0027] 5) CF₃,

[0028] 6) OCF₃,

[0029] 7) C₁₋₄ alkoxy, and

[0030] 8) cyano;

[0031] R¹² is a 5-membered heteroaryl ring having 2, 3, or 4heteroatoms, provided that at least 1 heteroatom is N, and at most 1 ofthe heteroatoms is S, said ring being unsubstituted or substituted, atany one ring atom, with CH₃.

[0032] In a class of compounds and pharmaceutically acceptable saltsthereof, R¹ is hydrogen, Cl, or CH₃.

[0033] In a group of this class of compounds and pharmaceuticallyacceptable salts thereof,

[0034] A is selected from the group consisting of

[0035] In a subgroup of this group of compounds and pharmaceuticallyacceptable salts thereof,

[0036] A is selected from the group consisting of

[0037] Z is selected from the group consisting of —CF₂CH₂—,—CH₂CH(CH₂N(CH₃)₂)—, —CH₂SO₂—, and —CH₂NH(CH₂)₃—;

[0038] X is N or CH;

[0039] R¹ is hydrogen, Cl, or CH₃; and

[0040] R² is selected from the group consisting of

[0041] Examples of this subgroup include

[0042] and pharmaceutically acceptable salts thereof.

[0043] The compounds of the present invention, may have chiral centersand occur as racemates, racemic mixtures and as individualdiastereomers, or enantiomers with all isomeric forms being included inthe present invention. The compounds of the present invention may alsohave polymorphic crystalline forms, with all polymorphic crystallineforms being included in the present invention.

[0044] When any variable occurs more than one time in any constituent orin formula I, its definition on each occurrence is independent of itsdefinition at every other occurrence. Also, combinations of substituentsand/or variables are permissible only if such combinations result instable compounds.

[0045] Some abbreviations that may appear in this application are asfollows:

Abbreviations

[0046] Designation AcOH acetic acid AIBN 2,2′-azobisisobutyronitrile(Boc)₂O di-t-butyl dicarbonate B(OMe)3 trimethyl borate B(O-iPr)3triisopropyl borate BuLi butyl lithium CHCl₃ chloroform CH₂Cl₂dichloromethane CH(OMe)₃ trimethylorthoformate Cs₂CO₃ cesium carbonateDAST diethylaminosulfurtrifluoride DBU1,8-diazabicyclo[5.4.0]undec-7-ene DCE 1,2-dichloroethane DIEAdiisopropylethylamine DMAP dimethylaminopyridine DMF dimethylformamideDPPA diphenylphosphoryl azide EDC1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride EtOAc ethylacetate EtOH ethanol Et₂O diethyl ether Et₃N triethylamine HClhydrochloric acid HOAc acetic acid HOAT 1-hydroxy-7-azabenzotriazoleH₂SO₄ sulfuric acid IPrOH 2-propanol KOH potassium hydroxide K₂CO₃potassium carbonate LAH lithium aluminum hydride LiCl lithium chlorideLiOH lithium hydroxide MCPBA m-chloroperoxybenzoic acid MeI iodomethaneMeOH methanol MgSO₄ magnesium sulfate n-BuLi n-butyllithium N₃PO(Ph)₂diphenyl phosphoryl azide NaBH₄ sodium borohydride NaHCO₃ sodiumhydrogen carbonate NaN₃ sodium azide NaOH sodium hydroxide Na₂CO₃ sodiumcarbonate Na₂SO₄ sodium sulfate Na₂S₂O₃ sodium thiosulfate NBSN-bromosuccinimide NCS N-chlorosuccinimide NH₄Cl ammonium chloride NH₄OHammonium hydroxide P(Ph)₃ triphenyl phosphine Pd-C palladium onactivated carbon catalyst Pd(PPh)₃ tetrakis triphenylphosphine palladiumPhCH₃ toluene POBr₃ phosphorous oxybromide TEA triethylamine Tf₂Otrifluoromethane sulfonic anhydride THF tetrahydrofuran SiO₂ siliconoxide SOCl₃ thionyl chloride SnCl₂ tin chloride Zn(CN)₂ zinc cyanide

[0047] As used herein except where noted, “alkyl” is intended to includeboth branched- and straight-chain saturated aliphatic hydrocarbon groupshaving the specified number of carbon atoms (Me is methyl, Et is ethyl,Pr is propyl, Bu is butyl); “alkoxy” represents a linear or branchedalkyl group of indicated number of carbon atoms attached through anoxygen bridge; “halogen”, as used herein, means fluoro, chloro, bromoand iodo; and “counterion” is used to represent a small, singlenegatively-charged species, such as chloride, bromide, hydroxide,acetate, trifluoroacetate, perchlorate, nitrate, benzoate, maleate,sulfate, tartrate, hemitartrate, benzene sulfonate, and the like.

[0048] The term “cycloC₃₋₇alkyl” is intended to include cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl, and the like.

[0049] The term “aryl” as used herein except where noted, represents astable 6- to 10-membered mono- or bicyclic ring system such as phenyl,or naphthyl. The aryl ring can be unsubstituted or substituted with oneor more of C₁₋₄ lower alkyl; hydroxy; alkoxy; halogen; amino.

[0050] The pyridyl N-oxide portion of the compounds of the invention arestructurally depicted using conventional representations

[0051] which have equivalent meanings.

[0052] In this specification methyl substituents may be represented by

[0053] For example, the structures

[0054] have equivalent meanings.

[0055] The pharmaceutically-acceptable salts of the compounds of FormulaI (in the form of water- or oil-soluble or dispersible products) includethe conventional non-toxic salts such as those derived from inorganicacids, e.g. hydrochloric, hydrobromoic, sulfuric, sulfamic, phosphoric,nitric and the like, or the quaternary ammonium salts which are formed,e.g., from inorganic or organic acids or bases. Examples of acidaddition salts include acetate, adipate, alginate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, citrate, camphorate,camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate,ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate,hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oxalate,pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, sulfate, tartrate, thiocyanate, tosylate, andundecanoate. Base salts include ammonium salts, alkali metal salts suchas sodium and potassium salts, alkaline earth metal salts such ascalcium and magnesium salts, salts with organic bases such asdicyclohexylamine salts, N-methyl-D-glucamine, and salts with aminoacids such as arginine, lysine, and so forth. Also, the basicnitrogen-containing groups may be quaternized with such agents as loweralkyl halides, such as methyl, ethyl, propyl, and butyl chloride,bromides and iodides; dialkyl sulfates like dimethyl, diethyl, dibutyl;and diamyl sulfates, long chain halides such as decyl, lauryl, myristyland stearyl chlorides, bromides and iodides, aralkyl halides like benzyland phenethyl bromides and others.

[0056] Thrombin Inhibitors—Therapeutic Uses—Method of Using

[0057] Anticoagulant therapy is indicated for the treatment andprevention of a variety of thrombotic conditions, particularly coronaryartery and cerebrovascular disease. Those experienced in this field arereadily aware of the circumstances requiring anticoagulant therapy. Theterm “patient” used herein is taken to mean mammals such as primates,including humans, sheep, horses, cattle, pigs, dogs, cats, rats, andmice.

[0058] Thrombin inhibition is useful not only in the anticoagulanttherapy of individuals having thrombotic conditions, but is usefulwhenever inhibition of blood coagulation is required such as to preventcoagulation of stored whole blood and to prevent coagulation in otherbiological samples for testing or storage. Thus, the thrombin inhibitorscan be added to or contacted with any medium containing or suspected ofcontaining thrombin and in which it is desired that blood coagulation beinhibited, e.g., when contacting the mammal's blood with materialselected from the group consisting of vascular grafts, stents,orthopedic prosthesis, cardiac prosthesis, and extracorporealcirculation systems.

[0059] Compounds of the invention are useful for treating or preventingvenous thromboembolism (e.g. obstruction or occlusion of a vein by adetached thrombus; obstruction or occlusion of a lung artery by adetached thrombus), cardiogenic thromboembolism (e.g. obstruction orocclusion of the heart by a detached thrombus), arterial thrombosis(e.g. formation of a thrombus within an artery that may cause infarctionof tissue supplied by the artery), atherosclerosis (e.g.arteriosclerosis characterized by irregularly distributed lipiddeposits) in mammals, and for lowering the propensity of devices thatcome into contact with blood to clot blood.

[0060] Examples of venous thromboembolism which may be treated orprevented with compounds of the invention include obstruction of a vein,obstruction of a lung artery (pulmonary embolism), deep vein thrombosis,thrombosis associated with cancer and cancer chemotherapy, thrombosisinherited with thrombophilic diseases such as Protein C deficiency,Protein S deficiency, antithrombin III deficiency, and Factor V Leiden,and thrombosis resulting from acquired thrombophilic disorders such assystemic lupus erythematosus (inflammatory connective tissue disease).Also with regard to venous thromboembolism, compounds of the inventionare useful for maintaining patency of indwelling catheters.

[0061] Examples of cardiogenic thromboembolism which may be treated orprevented with compounds of the invention include thromboembolic stroke(detached thrombus causing neurological affliction related to impairedcerebral blood supply), cardiogenic thromboembolism associated withatrial fibrillation (rapid, irregular twitching of upper heart chambermuscular fibrils), cardiogenic thromboembolism associated withprosthetic heart valves such as mechanical heart valves, and cardiogenicthromboembolism associated with heart disease.

[0062] Examples of arterial thrombosis include unstable angina (severeconstrictive pain in chest of coronary origin), myocardial infarction(heart muscle cell death resulting from insufficient blood supply),ischemic heart disease (local anemia due to obstruction (such as byarterial narrowing) of blood supply), reocclusion during or afterpercutaneous transluminal coronary angioplasty, restenosis afterpercutaneous transluminal coronary angioplasty, occlusion of coronaryartery bypass grafts, and occlusive cerebrovascular disease. Also withregard to arterial thrombosis, compounds of the invention are useful formaintaining patency in arteriovenous cannulas.

[0063] Examples of atherosclerosis include arteriosclerosis.

[0064] Examples of devices that come into contact with blood includevascular grafts, stents, orthopedic prosthesis, cardiac prosthesis, andextracorporeal circulation systems

[0065] The thrombin inhibitors of the invention can be administered insuch oral forms as tablets, capsules (each of which includes sustainedrelease or timed release formulations), pills, powders, granules,elixers, tinctures, suspensions, syrups, and emulsions. Likewise, theymay be administered in intravenous (bolus or infusion), intraperitoneal,subcutaneous, or intramuscular form, all using forms well known to thoseof ordinary skill in the pharmaceutical arts. An effective but nontoxicamount of the compound desired can be employed as an anti-aggregationagent. For treating ocular build up of fibrin, the compounds may beadministered intraocularly or topically as well as orally orparenterally.

[0066] The thrombin inhibitors can be administered in the form of adepot injection or implant preparation which may be formulated in such amanner as to permit a sustained release of the active ingredient. Theactive ingredient can be compressed into pellets or small cylinders andimplanted subcutaneously or intramuscularly as depot injections orimplants. Implants may employ inert materials such as biodegradablepolymers or synthetic silicones, for example, Silastic, silicone rubberor other polymers manufactured by the Dow-Corning Corporation.

[0067] The thrombin inhibitors can also be administered in the form ofliposome delivery systems, such as small unilamellar vesicles, largeunilamellar vesicles and multilamellar vesicles. Liposomes can be formedfrom a variety of phospholipids, such as cholesterol, stearylamine orphosphatidylcholines.

[0068] The thrombin inhibitors may also be delivered by the use ofmonoclonal antibodies as individual carriers to which the compoundmolecules are coupled. The thrombin inhibitors may also be coupled withsoluble polymers as targetable drug carriers. Such polymers can includepolyvinlypyrrolidone, pyran copolymer,polyhydroxy-propyl-methacrylamide-phenol,polyhydroxyethyl-aspartamide-phenol, or polyethyleneoxide-polylysinesubstituted with palmitoyl residues. Furthermore, the thrombininhibitors may be coupled to a class of biodegradable polymers useful inachieving controlled release of a drug, for example, polylactic acid,polyglycolic acid, copolymers of polylactic and polyglycolic acid,polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters,polyacetals, polydihydropyrans, polycyanoacrylates and cross linked oramphipathic block copolymers of hydrogels.

[0069] The dosage regimen utilizing the thrombin inhibitors is selectedin accordance with a variety of factors including type, species, age,weight, sex and medical condition of the patient; the severity of thecondition to be treated; the route of administration; the renal andhepatic function of the patient; and the particular compound or saltthereof employed. An ordinarily skilled physician or veterinarian canreadily determine and prescribe the effective amount of the drugrequired to prevent, counter, or arrest the progress of the condition.

[0070] Oral dosages of the thrombin inhibitors, when used for theindicated effects, will range between about 0.01 mg per kg of bodyweight per day (mg/kg/day) to about 30 mg/kg/day, preferably 0.025-7.5mg/kg/day, more preferably 0.1-2.5 mg/kg/day, and most preferably0.1-0.5 mg/kg/day (unless specificed otherwise, amounts of activeingredients are on free base basis). For example, an 80 kg patient wouldreceive between about 0.8 mg/day and 2.4 g/day, preferably 2-600 mg/day,more preferably 8-200 mg/day, and most preferably 840 mg/kg/day. Asuitably prepared medicament for once a day administration would thuscontain between 0.8 mg and 2.4 g, preferably between 2 mg and 600 mg,more preferably between 8 mg and 200 mg, and most preferably 8 mg and 40mg, e.g., 8 mg, 10 mg, 20 mg and 40 mg. Advantageously, the thrombininhibitors may be administered in divided doses of two, three, or fourtimes daily. For administration twice a day, a suitably preparedmedicament would contain between 0.4 mg and 4 g, preferably between 1 mgand 300 mg, more preferably between 4 mg and 100 mg, and most preferably4 mg and 20 mg, e.g., 4 mg, 5 mg, 10 mg and 20 mg.

[0071] Intravenously, the patient would receive the active ingredient inquantities sufficient to deliver between 0.025-7.5 mg/kg/day, preferably0.1-2.5 mg/kg/day, and more preferably 0.1-0.5 mg/kg/day. Suchquantities may be administered in a number of suitable ways, e.g. largevolumes of low concentrations of active ingredient during one extendedperiod of time or several times a day, low volumes of highconcentrations of active ingredient during a short period of time, e.g.once a day. Typically, a conventional intravenous formulation may beprepared which contains a concentration of active ingredient of betweenabout 0.01-1.0 mg/ml, e.g. 0.1 mg/ml, 0.3 mg/ml, and 0.6 mg/ml, andadministered in amounts per day of between 0.01 ml/kg patient weight and10.0 ml/kg patient weight, e.g. 0.1 ml/kg, 0.2 ml/kg, 0.5 ml/kg. In oneexample, an 80 kg patient, receiving 8 ml twice a day of an intravenousformulation having a concentration of active ingredient of 0.5 mg/ml,receives 8 mg of active ingredient per day. Glucuronic acid, L-lacticacid, acetic acid, citric acid or any pharmaceutically acceptableacid/conjugate base with reasonable buffering capacity in the pH rangeacceptable for intravenous administration may be used as buffers.Consideration should be given to the solubility of the drug. The choiceof appropriate buffer and pH of a formulation, depending on solubilityof the drug to be administered, is readily made by a person havingordinary skill in the art.

[0072] The compounds can also be administered in intranasal form viatopical use of suitable intranasal vehicles, or via transdermal routes,using those forms of transdermal skin patches well known to those ofordinary skill in that art. To be administered in the form of atransdermal delivery system, the dosage administration will, or course,be continuous rather than intermittent throughout the dosage regime.

[0073] The thrombin inhibitors are typically administered as activeingredients in admixture with suitable pharmaceutical diluents,excipients or carriers (collectively referred to herein as “carrier”materials) suitably selected with respect to the intended form ofadministration, that is, oral tablets, capsules, elixers, syrups and thelike, and consistent with convention pharmaceutical practices.

[0074] For instance, for oral administration in the form of a tablet orcapsule, the active drug component can be combined with an oral,non-toxic, pharmaceutically acceptable, inert carrier such as lactose,starch, sucrose, glucose, methyl cellulose, magnesium stearate,dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like;for oral administration in liquid form, the oral drug components can becombined with any oral, non-toxic, pharmaceutically acceptable inertcarrier such as ethanol, glycerol, water and the like. Moreover, whendesired or necessary, suitable binders, lubricants, distintegratingagents and coloring agents can also be incorporated into the mixture.Suitable binders include starch, gelatin, natural sugars such as glucoseor beta-lactose, corn-sweeteners, natural and synthetic gums such asacacia, tragacanth or sodium alginate, carboxymethylcellulose,polyethylene glycol, waxes and the like. Lubricants used in these dosageforms include sodium oleate, sodium stearate, magnesium stearate, sodiumbenzoate, sodium acetate, sodium chloride and the like. Disintegratorsinclude, without limitation, starch methyl cellulose, agar, bentonite,xanthan gum and the like.

[0075] The invention also includes a method for treating an inflammatorydisease in a patient which comprises treating the patient with acomposition comprising a compound of the present invention. Suchdiseases include but are not limited to nephritis, systemic lupuserythematosus, rheumatoid arthritis, glomerulonephritis, and sacoidosis.

[0076] The invention is also a method for treating an inflammatorydisease in a patient that comprises treating the patient with acombination comprising a compound of the invention and an NSAID, e.g., aCOX-2 inhibitor. Such diseases include but are not limited to nephritis,systemic lupus, erythematosus, rheumatoid arthritis, glomerulonephritis,vasculitis and sacoidosis.

[0077] The present invention is a method for relieving pain, fever andinflammation of a variety of conditions including nephritis, systemiclupus erythematosus, rheumatoid arthritis, glomerulonephritis,sacoidosis, rheumatic fever, symptoms associated with influenza or otherviral infections, common cold, low back and neck pain, dysmenorrhea,headache, toothache, sprains and strains, myositis, neuralgia,synovitis, arthritis, including rheumatoid arthritis degenerative jointdiseases (osteoarthritis), gout and ankylosing spondylitis, bursitis,burns, injuries, following surgical and dental procedures in a patientby administering to the patient a therapeutically effective amount of acompound of the invention. Thrombin inhibitors may also be useful forthe treatment of dementia including pre-senile and senile dementia, andin particular, dementia associated with Alzheimer Disease.

[0078] In inflammatory diseases wherein fibrin formation is prominent,the fibrin may be a determinant of the pathology. Fibrin serves as amatrix onto which inflammatory cells can migrate and adhere. (seeSherman et al., 1977 J. Exp. Med. 145:76-85; Altieri et al., 1986 J.Clin. Invest. 78:968-976; Wright et al., 1983 Proc. Natl. Acad. Sci.85:7734-7738; Altieri et al., 1993 J. Biol. Chem. 268;1847-1853). Fibrinalso enhances expression of the inflammatory cytokine IL-1beta anddecreases expression of IL-1 receptor antagonist by human peripheralblood mononuclear cells (see Perez 1995 J. Immunol. 154:1879-1887). Theanticoagulants warfarin and heparin attenuate delayed-typehypersensitivity reactions and experimental nephritis in animals. (seeJasain et al., Immunopathogenesis of Rheumatoid Arthritis Eds. G.S.Panayi et al., Surrey, UK, Reedbooks, Ltd. and Halpern et al., 1965Nature 205:257-259). Enzymatic defibrination with ancrod diminishes thedegree of experimental nephritis (Naish et al., 1972 Clin. Sci.42:643-646), systemic lupus erythematosus (Cole et al., 1990 Kidney Int.37:29-35, and rheumatoid arthritis (see Busso et al., 1998 J. Clin.Invest. 102:41-50) in animals, and glomerulonephritis in man (see Kim etal., 1988 Q. J. Med. 69:879-905). Additionally, intra articularinjection of fibrin induces arthritis in rabbits immunized with fibrinDumonde et al., 1961 British Journal of Experimental PathologyXLIII:373-383), and antigen-induced arthritis in mice is exacerbated inurokinase-deficient mice wherein fibrinolysis synovial fibrin iscompromised (see Busso et al., 1998 J. Clin. Invest. 102:41-50).

[0079] In diseases where fibrin deposition is prominent such as, but notlimited to, rheumatoid arthritis, systemic lupus erythematosus,glomerulonephritis, vasculitis and sacoidosis, lowering the steady stateconcentration of fibrin by administration of a compound of the inventionwill, according to the instant invention, diminish the pathologicalinflammatory responses associated with these diseases.

[0080] Similarly, compounds of the invention will be useful as a partialor complete substitute for conventional NSAIDs in preparations whereinthey are presently co-administered with other agents or ingredients.Thus in further aspects, the invention encompasses pharmaceuticalcompositions for treating inflammatory diseases as defined abovecomprising a non-toxic therapeutically effective amount of a compound ofthe invention as defined above and one or more ingredients such asanother pain reliever including acetominophen or phenacetin; apotentiator including caffeine; an H2-antagonist, aluminum or magnesiumhydroxide, simethicone, a decongestant including phenylephrine,phenylpropanolamine, pseudophedrine, oxymetazoline, ephinephrine,naphazoline, xylometazoline, propylhexedrine, or levodesoxyephedrine; anantiitussive including codeine, hydrocodone, caramiphen, carbetapentane,or dextramethorphan; a diuretic; a sedating or non-sedatingantihistamine. In addition the invention encompasses a method oftreating inflammatory diseases comprising administration to a patient inneed of such treatment a non-toxic therapeutically effect amount of acompound of the invention, optionally co-administered with one or moreof such ingredients as listed immediately above.

[0081] The instant invention also involves a novel combination therapycomprising the administration of a therapeutically effective amount ofan NSAID such as a COX-2 inhibitor in combination with a therapeuticallyeffective amount, as descried above, of a compound of the invention to amammal, and more particularly, to a human. The combination therapy isused to treat inflammatory diseases.

[0082] The instant pharmaceutical combinations comprising a compound ofthe invention, in therapeutically effective amounts described above, incombination with an NSAID such as a COX-2 inhibitor includeadministration of a single pharmaceutical dosage formulation whichcontains both a compound of the invention and the NSAID, as well asadministration of each active agent in its own separate pharmaceuticaldosage formulation. Where separate dosage formulations are used, thecompund of the invention and the NSAID can be administered atessentially the same time, i.e., concurrently, or at separatelystaggered times, i.e, sequentially. The “instant pharmaceuticalcombination” is understood to include all these regimens. Administrationin these various ways are suitable for the present invention as long asthe beneficial pharmaceutical effect of the compound of the inventionand the NSAID are realized by the patient at substantially the sametime. Such beneficial effect is preferably achieved when the targetblood level concentrations of each active drug are maintained atsubstantially the same time. It is preferred that the compound of theinvention and the NSAID be co-administered concurrently on a once-a-daydosing schedule; however, varying dosing schedules, such as the compoundof the invention once per day and the NSAID once, twice or more timesper day, or the NSAID once per day and the compound of the inventiononce, twice or more times per day, is also encompassed herein. A singleoral dosage formulation comprised of both the compound of the inventionand the NSAID is preferred. A single dosage formulation will provideconvenience for the patient.

[0083] The instant invention also provides pharmaceutical compositionscomprised of a therapeutically effective amount of an NSAID, or apharmaceutically acceptable salt thereof, in combination with atherapeutically effective amount of a compound of the invention, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier. One embodiment of the instant compositions is asingle composition adapted for oral administration comprised of atherapeutically effective amount of a COX-2 inhibitor in combinationwith a therapeutically effective amount of a compound of the inventionand a pharmaceutically acceptable carrier. The combination can also beadministered in separate dosage forms, each having one of the activeagents. If administered in separate dosage forms, the separate dosageforms are administered such that the beneficial effect of each activeagent is realized by the patient at substantially the same time.

[0084] Common NSAIDs include salicylates such as aspirin, sodiumsalicylate, choline salicylate, salicylsalicylic acid, diflunisal, andsalsalate; indoleacetic acids such as indomethacin and sulindac;pyrazoles such as phenylbutazone, oxyphenbutazone; pyrrolealkanoic acidssuch as tolmetin; phenylacetic acids such as ibuprofen, feroprofen,flurbiprofen, and ketoprofen; fenamates such as mefanamic acid, andmeclofenamate; oxicams such as piroxicam; and naphthaleneacetic acidssuch as naproxen. Cyclo-oxygenase inhibitors such as COX-1 and COX-2inhibitors are also NSAIDs.

[0085] Employing the human whole blood COX-1 assay and the human wholeblood COX-2 assay described in C. Brideau et al, Inflamm. Res. 45: 68-74(1996), herein incorporated by reference, preferably, the compounds havea cyclooxygenase-2 IC50 of less than about 2 μM in the human whole bloodCOX-2 assay, yet have a cyclooxygenase-1 IC₅₀ of greater than about 5 μMin the human whole blood COX-1 assay. Also preferably, the compoundshave a selectivity ratio of cyclooxygenase-2 inhibition overcyclooxygenase-1 inhibition of at least 10, and more preferably of atleast 40. The resulting selectivity may indicate an ability to reducethe incidence of common NSAID-induced side effects.

[0086] The inhibitor of cyclooxygenase-2 may be administered at a dosagelevel up to conventional dosage levels for NSAIDs. Suitable dosagelevels will depend upon the antiinflammatory effect of the choseninhibitor of cyclooxygenase-2, but typically suitable levels will beabout 0.001 to 50 mg/kg per day, preferably 0.005 to 30 mg/kg per day,and especially 0.05 to 10 mg/kg per day, e.g., 12.5 mg once each day or25 mg once each day. The compound may be administered on a regimen of upto 6 times per day, preferably 1 to 4 times per day, and especially onceper day.

[0087] The dosage regimen utilizing a compound of the invention incombination with the NSAID is selected in accordance with a variety offactors including type, species, age, weight, sex and medical conditionof the patient; the severity of the condition to be treated; the routeof administration; the renal and hepatic function of the patient; andthe particular compound or salt or ester thereof employed. Since twodifferent active agents are being used together in a combinationtherapy, the potency of each of the agents and the interactive effectsachieved by combining them together must also be taken into account. Aconsideration of these factors is well within the purview of theordinarily skilled clinician for the purpose of determining thetherapeutically effective or prophylactically effective dosage amountsneeded to prevent, counter, or arrest the progress of the condition.

[0088] Administration of the drug combination to the patient includesboth self-administration and administration to the patient by anotherperson.

[0089] Additional active agents may be used in combination with thecompound of the invention in a single dosage formulation, or may beadministered to the patient in a separate dosage formulation, whichallows for concurrent or sequential administration. Examples ofadditional active agents which may be employed include HMG-CoA synthaseinhibitors; squalene epoxidase inhibitors; squalene synthetaseinhibitors (also known as squalene synthase inhibitors), acyl-coenzyrneA: cholesterol acyltransferase (ACAT) inhibitors; probucol; niacin;fibrates such as clofibrate, fenofibrate, and gemfibrizol; cholesterolabsorption inhibitors; bile acid sequestrants; LDL (low densitylipoprotein) receptor inducers; vitamin B₆ (also known as pyridoxine)and the pharmaceutically acceptable salts thereof such as the HCl salt;vitamin B₁₂ (also known as cyanocobalamin); β-adrenergic receptorblockers; folic acid or a pharmaceutically acceptable salt or esterthereof such as the sodium salt and the methylglucamine salt; andanti-oxidant vitamins such as vitamin C and E and beta carotene.

[0090] The thrombin inhibitors can also be co-administered with suitableanti-platelet agents, including, but not limited to, fibrinogen receptorantagonists (e.g. to treat or prevent unstable angina or to preventreocclusion after angioplasty and restenosis), anticoagulants such asaspirin, thrombolytic agents such as plasminogen activators orstreptokinase to achieve synergistic effects in the treatment of variousvascular pathologies, or lipid lowering agents includingantihypercholesterolemics (e.g. HMG CoA reductase inhibitors such aslovastatin and simvastatin, HMG CoA synthase inhibitors, etc.) to treator prevent atherosclerosis. For example, patients suffering fromcoronary artery disease, and patients subjected to angioplastyprocedures, would benefit from coadministration of fibrinogen receptorantagonists and thrombin inhibitors. Also, thrombin inhibitors enhancethe efficiency of tissue plasminogen activator-mediated thrombolyticreperfusion. Thrombin inhibitors may be administered first followingthrombus formation, and tissue plasminogen activator or otherplasminogen activator is administered thereafter.

[0091] Typical doses of thrombin inhibitors of the invention incombination with other suitable anti-platelet agents, anticoagulationagents, or thrombolytic agents may be the same as those doses ofthrombin inhibitors administered without coadministration of additionalanti-platelet agents, anticoagulation agents, or thrombolytic agents, ormay be substantially less that those doses of thrombin inhibitorsadministered without coadministration of additional anti-plateletagents, anticoagulation agents, or thrombolytic agents, depending on apatient's therapeutic needs.

[0092] Unless otherwise stated, all NMR determinations were made using400 MHz field strength.

[0093] The compounds claimed in this invention can be prepared via theschemes described below. In general, 2-heterocyclic benzylamines werecoupled with various pyrazinone or pyridinone carboxylic acids toproduce the claimed compounds:

[0094] where A-Z is, for example,

[0095] 2,2-difluoro-2-pyridin-2-yl-ethylamino,

[0096] 2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino,

[0097] (cyclopropylmethyl-amino)-propylamino,

[0098] 1-dimethylaminomethyl-2-phenyl-ethylamino, or

[0099] phenylmethanesulfonylamino;

[0100] X is N or CH;

[0101] R¹ is Cl or hydrogen;

[0102] R¹² is a 5-membered heterocyclic ring;

[0103] R³ is Cl or hydrogen; and

[0104] W is CH or N.

[0105] The synthesis of the benzylamines is depicted in schemes 1through 10 and the carboxylic acids are found in schemes 11 through 16.

[0106] In scheme 1, the thiadiazole ring was synthesized via cyclizationof 1-1 with thionyl chloride. Functional group transformation of themethyl group of 1-2 to the benzylamine was accomplished in three stepsvia the methyl bromide and methyl azide.

[0107] Cyclization with formamide to the imidazole 2-2 is depicted inscheme 2. Protection of the imidazole group with trityl, conversion ofthe phenyl bromide to the nitrile and subsequent reduction gave thebenzylamine, 2-6.

[0108] In scheme 3, an aminobenzoic acid was converted to the tetrazole3-1 or 4 through cyclization with sodium azide and trimethylorthoformate. The carboxylic acid of 3-1 or 4 was converted to the amideand then to the nitrile which was reduced to the amine 3-4 or 4.

[0109] The pyrazole ring of 5-1 was formed from 2-hydrazinobenzoic acidand malonaldehyde bis-dimethylacetal as shown in scheme 4. Thecarboxylic acid was converted to the amide which was then reduced togive 5-3.

[0110] In scheme 5 phthalonitrile was cyclized to the imidazole, 6-2 viathe benzimidic acid 6-1. Reduction of the nitrite afforded 6-4.

[0111] In scheme 6, the fluorine atom of 2-cyano-3-fluoropyridine wasdisplaced with [1,2,4]-triazole to give 7-1 and with tetrazole to give11-1. Reduction yielded the respective benzylamines 7-3 and 11-2.

[0112] Chlorine was displaced by [1,2,4]-triazole in scheme 7 to give8-1 with subsequent reduction to 8-2.

[0113] In scheme 8, displacement of fluorine on 2-fluorocyanobenzenegave two regioisomers, 9-1 which were reduced to 9-2 and 10-1.Displacement with imidazole and reduction gave 13-2.

[0114] Pyrazole was protected as its THP derivative in scheme 9 to give12-1 which was then reacted with triisopropyl borate and deprotected togive the boronic acid, 12-2. Palladium mediated coupling of thiscompound with Boc protected bromobenzylamine, 12-3 gave 12-4. Removal ofthe Boc group gave 12-5.

[0115] The final benzylamine synthesis, shown in scheme 10 begins with2-bromomethyl-benzonitrile. Displacement of bromine with azide followedby reduction and concurrent protection of the benzylamine with a Bocgroup gave 14-2. Cyclization to the tetrazole 14-3 was afforded withsodium azide and ammonium chloride. Boc removal gave 14-4. Reaction of14-3 with iodomethane gave two regioisomers, 15-1 which were thendeprotected to give 15-2 and 16-1.

[0116] As shown in scheme 11, the synthesis of the2,2-difluoro-2-pyridin-2-yl-ethylamine, 17-6 involved generation of2-lithiopyridine from 2-bromopyridine in ether, followed by reactionwith diethyl oxalate to give the ketoester, 17-1. Treatment with excessdiethylaminosulfurtrifluoride provided the difluoro compound, 17-2 whichwas reduced using sodium borohydride. The resulting2,2-difluoro-2-pyridin-2-yl-ethanol was converted to the correspondingtriflate using triflic anhydride and 2,6-di-t-butyl-4-methylpyridine asthe base. The crude triflate was then treated with sodium azide in DMFto give the azide, 17-5. Reduction of the azide by catalytichydrogenation provided the 2,2-difluoro-2-pyridin-2-yl-ethylamine, 17-6.The pyridine N-oxide, 18-2 was prepared by treating the azideintermediate, 18-1 with mCPBA and then reducing the azide withtriphenylphosphine.

[0117] Scheme 12 depicts the synthesis of the bromopyrazinone, 17-10.Ethyl glycine was reacted with ethyl oxalyl chloride to afford an amide,17-7 which was then reacted with aminoacetaldehyde dimethyl acetal togive diamide, 17-8. The material was cyclized to a pyrazine dione withHCl. The pyrazine dione was reacted with phosphorous oxybromide toafford the bromopyrazinone, 17-10.

[0118] Condensation of the products from schemes 11 and 12 wasaccomplished by heating in toluene/ethanol. Scheme 13 depicts thereaction with 2,2-difluoro-2-pyridin-2-yl-ethylamine, 17-6 and scheme 14shows the identical reaction 5 sequence with the N-oxide, 18-2. In bothschemes the ethyl esters of the condensed products were hydrolized tothe carboxylic acids, 19-1 and 20. The pyrazinone ring was chlorinatedusing N-chlorosuccinimide to give 17-12 and 18-4 which were thenhydrolized to the carboxylic acids, 17-13 and 18-5.

[0119] Scheme 15 depicts a reaction sequence leading to a pyrazinonebearing an alkyl cyclopropyl moiety. Cyclopropanecarboxaldehyde wasreductively aminated with a Cbz-protected diamine to give 21-1.Protecting group manipulation yielded the Boc-diamine, 21-3. Reactionwith the bromo pyrazinone, 17-10 and subsequent hydrolysis of the ethylester gave the carboxylic acid, 21-5. Chlorination of the pyrazinone,21-4 and hydrolysis gave 22-2.

[0120] In scheme 16, the bromopyrazinone, 17-10 was reacted with(S)-1-azidomethyl-2-phenyl-ethylamine by heating. Chlorination of thepyrazinone ring and reduction of the azide yielded 23-3. The primaryamine was reductively aminated with formaldehyde and the ester washydrolyzed to give the amino acid pyrazinone, 23-5.

[0121] Examples 24 through 63 depict the products resulting from amidecouplings between the heterocyclic benzylamines (schemes 1-10, examples1-16) and the pyrazinone or pyridinone carboxylic acids (schemes 11-16,examples 17-23). A general coupling procedure employed the followingreagents: 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride(EDC), 1-hydroxy-7-azabenzotriazole (HOAt) and a tertiary base(diisopropylethylamine, for ex).

EXAMPLE 1

[0122] 2-[1,2,3]Thiadiazole-4-yl-benzylamine

[0123] Step A

[0124] N′-(1-o-Tolyl-ethylidene)-hydrazinecarboxylic Acid Ethyl Ester(1-1)

[0125] A solution of 2′-methylacetophenone (0.98 ml, 7.4 mmol), ethylcarbazate (0.81 g, 7.8 mmol) and p-toluenesulfonic acid monohydrate (70mg, 0.37 mmol) in toluene (30 ml) was heated at reflux temperature witha Dean-Stark apparatus for 2 h. Solvent evaporation and flashchromatography (silica gel, hexane-ethyl acetate, 80:20) gaveN′-(1-o-tolyl-ethylidene)-hydrazinecarboxylic acid ethyl ester; ¹H NMR(CDCl₃, 400 MHz) δ 7.72 (bs, 1H), 7.21 (m, 4H), 4.31 (q, 2H, J=7.1 Hz),2.37 (s, 3H), 2.17 (s, 3H), 1.34 (t, 3H, J=7.1 Hz).

[0126] Step B

[0127] 4-o-Tolyl-[1,2,31thiadiazole (1-2)

[0128] To thionyl chloride (1 ml), cooled to 0° C. was addedN′-(1-o-tolyl-ethylidene)-hydrazinecarboxylic acid ethyl ester. Thereaction mixture was heated to 60° C. for 1h. Solvent evaporation gave4-o-tolyl-[1,2,3]thiadiazole; ¹H NMR (CDCl₃, 400 MHz) δ 8.51 (s, 1H),7.65 (d, 1H, J=7.3 Hz), 7.36 (m, 3H), 2.46 (s, 3H).

[0129] Step C

[0130] 4-(2-Bromomethyl-phenyl)-[1,2,3]thiadiazole (1-3)

[0131] A solution of 4-o-tolyl-[1,2,3]thiadiazole (100 mg, 0.57 mmol),N-bromosuccinimide (100 mg, 0.57 mmol) and 2,2′-azobisisobutyronitrile(9.4 mg, 0.057 mmol) in chloroform (10 ml) was heated at refluxtemperature for ˜18 h. Additional chloroform was added and the mixturewas washed with water, 5% sodium thiosulfate solution and brine. Dryingand solvent evaporation gave4-(2-bromomethyl-phenyl)-[1,2,3]thiadiazole; ¹H NMR (CDCl₃, 300 MHz) δ8.87 (s, 1H), 7.67-7.39 (m, 4H), 4.71 (s, 2H).

[0132] Step D

[0133] 4-(2-Azidomethyl-phenyl)-[1,2,3]thiadiazole (1-4)

[0134] A solution of 4-(2-bromomethyl-phenyl)-[1,2,3]thiadiazolc (7.0 g,0.027 mol) and sodium azide (5.3 g, 0.081 mol) in N,N-dimethylformamide(200 ml) was stirred at room temperature overnight. Ethyl acetate wasadded and the reaction mixture was washed with water and brine. Dryingand solvent evaporation gave an oil; flash chromatography (silica gel,hexane-ethyl acetate, 96:4) gave4-(2-azidomethyl-phenyl)-[1,2,3]thiadiazole; ¹H NMR (CDCl₃, 300 MHz) δ8.74 (s, 1H), 7.76 (m, 1H), 7.53 (m, 3H), 4.54 (s, 2H).

[0135] Step E

[0136] 2-[1,2,3]Thiadiazole-4-yl-benzylamine (1-5)

[0137] A solution of 4-(2-azidomethyl-phenyl)-[1,2,3]thiadiazole (1.0 g,4.6 mmol), triphenylphosphine (1.4 g, 5.5 mmol) and water (0.12 ml, 6.9mmol) in tetrahydrofuran (20 ml) was stirred at room temperatureovernight. Solvent evaporation and flash chromatography (silica gel,chloroform-2-propanol, 95:5-92:8) gave2-[1,2,3]thiadiazole-4-yl-benzylamine; ¹H NMR (CDCl₃, 300 MHz) δ 8.87(s, 1H), 7.67 (d, 1H, J=8 Hz), 7.45 (m, 3H), 3.88 (s, 2H).

EXAMPLE 2

[0138] 2-(1-Trityl-1H-imidazol-4-yl)-benzylamine Oxalate Salt

[0139] Step A

[0140] 2-Bromo-1-(2-bromo-phenyl)-ethanone (2-1)

[0141] To a solution of 2-bromo-acetophenone (75.0 g, 0.37 mol) inmethanol (220 ml) was added trimethyl borate (55 ml, 0.48 mol). Thissolution was stirred at room temperature under nitrogen for 45 min. Thenbromine (20.4 ml, 0.39 mol) was added dropwise over 2 h. The reactiontemperature was closely monitored and maintained between 23 to 27° C.Below 23° C. product formation was slow and above 27° C. there wassignificant dibromoketone formation. The reaction was stirred for anadditional 1 h. At this point the reaction consisted of a mixture of2-bromo-1-(2-bromo-phenyl)ethanone and the dimethylketal as the majorproducts (by GC). Water (220 ml) was added and the mixture was heated toreflux ˜74° C. for 40 min. After cooling, two phases separated.Concentration of the bottom layer afforded a yellow oil as the product.This oil was used for the next step without further purification.

[0142] Step B

[0143] 4-(2-Bromo-phenyl)-1H-imidazole (2-2)

[0144] To a 1 liter, three neck flask containing2-bromo-1-(2-bromo-phenyl)-ethanone (95 g, 340 mmol) was added formamide(240.0 ml, 6.8 mol). The resulting two phase mixture was heated to 145°C. for 14 h under nitrogen. At this temperature the reaction solutionwas homogeneous. The progress of the reaction was monitored by TLC(silica gel, ethyl acetate), product R_(f)=0.23. After cooling, thereaction was diluted with ethyl acetate (500 ml). To this solution wasadded 15% aqueous potassium carbonate solution (440 ml) in portionswhile stirring. The phases that formed were separated. The aqueous layerwas extracted with ethyl acetate (175 ml×2). The combined organic layerwas then washed with brine (50 ml×2), dried (sodium sulfate) andconcentrated in vacuo to yield an amber solid.

[0145] Step C

[0146] 4-(2-Bromo-phenyl)-1-trityl-1H-imidazole (2-3)

[0147] To a solution of crude 4-(2-bromo-phenyl)-1H-imidazole (73.5 g,0.33 mol) and triethylamine (45.8 ml, 0.33 mol) in dry dimethylformamide(750 ml) at 0° C. was added a solution of trityl chloride in drydimethylformamide (850 ml) dropwise over 40 min. When the addition wascomplete, the ice bath was removed and the reaction was stirred at roomtemperature for 1.5 h. Then the reaction mixture was poured into astirring mixture of ice water (ca. 2.0 L). A light orange solidprecipitated. After stirring for 20 min the solid was filtered and driedto give a light amber solid. This solid was used in the next reactionwithout further purification.

[0148] Step D

[0149] 2-(1-Trityl-1H-imidazol-4-yl)-benzonitrile (2-4)

[0150] To a solution of 4-(2-bromo-phenyl)-1-trityl-1H-imidazole (73.0g, 163.3 mmol) in dimethylformamide (500 ml) was added copper (I)cyanide (17.5 g, 195.9 mmol). The reaction was heated to ˜80° C. undernitrogen for 14 h. After cooling to about 50° C., the reaction wasdiluted with toluene (ca. 300 ml) and slowly poured onto ammoniumhydroxide (3N, 1.5 L) while stirring vigorously. The mixture was stirredfor 40 min and then filtered in vacuo over a bed of celite (slowfiltration, required ˜2 h). The phases were separated and the organiclayer was washed with brine (75 ml×3) and dried (sodium sulfate).Concentration of the solvent afforded a light brown solid. The crudeproduct contains ˜10-15% of trityl alcohol (by HPLC) and was usedwithout further purification in the subsequent step.

[0151] Step E

[0152] 2-(1-Trityl-1H-imidazol-4-yl)-benzylamine (2-5)

[0153] 2-(1-Trityl-1H-imidazol-4-yl)-benzonitrile (17.6 g, 42.7 mmol)was dissolved in dry tetrahydrofuran (320 ml) and stirred under nitrogenin an ice bath. To this solution was added lithium aluminum hydride (1.0M in THF, 45 ml, 45 mmol) dropwise over 15 min. After the addition wascomplete the ice bath was removed and the reaction was stirred at roomtemperature. The reaction was closely monitored by HPLC and wastypically complete within 45 min to 1.5 h. This close monitoring wasessential because with longer reaction times, the amount of deprotectedimidazole increased. Once complete, the reaction was diluted withtetrahydrofuran (200 ml) and quenched with water (1.7 ml), 15% sodiumhydroxide solution (1.7 ml) and water (5.1 ml). This mixture was stirredat room temperature for 3 h. The solid was filtered over a layer ofcelite and rinsed with tetrahydrofuran (200 ml). Rotary evaporation ofthe filtrate afforded 2-(1-trityl-1H-imidazol-4-yl)-benzylamine as athick amber oil.

[0154] Step F

[0155] 2-(1-Trityl-1H-imidazol-4-yl)-benzylamine Oxalate Salt (2-6)

[0156] The crude 2-(1-trityl-1H-imidazol-4-yl)-benzylamine (66.1 g, 159mmol) was dissolved in tetrahydrofuran (420 ml). Solid oxalic acid (14.3g, 159 mmol) was added to the solution while stirring. This mixture wasstirred at room temperature for 15 min and then added dropwise tostirring hexane (2000 ml). Tetrahydrofuran (100 ml) was used to rinsethe glassware. A yellow solid precipitated. The mixture was stirred foran additional 20 min and the product was isolated by filtration. Thesolid was rinsed with 4:1 hexane:tetrahydrofuran (625 ml) and dried in avacuum oven at ˜45° C. with an air purge for 18 h to afford2-(1-trityl-1H-imidazol-4-yl)-benzylamine oxalate salt; MS (ES+) M+1416.6 for C₂₉H₂₅N₃.

EXAMPLE 3

[0157] 2-Tetrazol-1-yl-benzylamine

[0158] Step A

[0159] 2-Tetrazol-1-yl-benzoic Acid (3-1)

[0160] A suspension of 2-aminobenzoic acid (6.0 g, 0.044 mol), trimethylorthoformate (14.2 ml, 0.13 mol) and sodium azide (8.4 g, 0.13 mol) inglacial acetic acid (150 ml) was stirred at room temperature for 2 h.Filtration and concentration from toluene gave 2-tetrazol-1-yl-benzoicacid; ¹H NMR (CD₃OD, 400 MHz) δ 9.47 (s, 1H), 8.19 (dd, 1H, J=7.7 Hz,J=1.6 Hz), 7.79 (m, 2H), 7.61 (dd, 1H, J=7.7 Hz, J=1.5 Hz).

[0161] Step B

[0162] 2-Tetrazol-1-yl-benzamide (3-2)

[0163] A solution of 2-tetrazol-1-yl-benzoic acid (1.0 g, 5.2 mmol),ammonium chloride (0.56 g, 10.4 mmol),1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (2.0 g, 10.4mmol), 1-hydroxy-7-azabenzotriazole (1.4 g, 10.4 mmol) anddiisopropylethylamine (3.6 ml, 20.8 mmol) in N,N-dimethylformamide (15ml) was stirred at room temperature overnight. Water was added and thereaction mixture was extracted with ethyl acetate. The combined organiclayers were washed with brine. Drying and solvent evaporation gave2-tetrazol-1-yl-benzamide; ¹H NMR (CD₃OD, 400 MHz) δ 9.44 (s, 1H), 7.72(m, 4H).

[0164] Step C

[0165] 2-Tetrazol-1-yl-benzonitrile (3-3)

[0166] To a solution of 2-tetrazol-1-yl-benzamide (1.5 g, 7.9 mmol) intetrahydrofuran (50 ml) was added (methoxycarbonylsulfamoyl)ammoniumhydroxide, inner salt (2.8 g, 11.8 mmol) in three portions over 1.5 h.Water was added and the reaction mixture was extracted with ethylacetate. The combined organic layers were washed with brine. Drying andsolvent evaporation gave 2-tetrazol-1-yl-benzonitrile; ¹H NMR (CDCl₃,400 MHz) δ 9.27 (s, 1H), 7.90 (m, 3H), 7.72 (m, 1H).

[0167] Step D

[0168] 2-Tetrazol-1-yl-benzylamine (3-4)

[0169] A solution of 2-tetrazol-1-yl-benzonitrile (1.3 g, 7.6 mmol) inethanol saturated with ammonia (125 ml) was stirred in the presence ofRaney nickel (50% slurry in water, washed with ethanol, catalyticamount) under a hydrogen atmosphere overnight. The reaction mixture wasfiltered over celite and concentrated to give2-tetrazol-1-yl-benzylamine; ¹H NMR (CDCl₃, 400 MHz) δ 9.28 (s, 1H),7.59 (m, 2H), 7.47 (m, 2H), 3.70 (s, 2H).

EXAMPLE 4

[0170] 5-Chloro-2-tetrazol-1-yl-benzylamine (4)

[0171] Prepared following a similar protocol as described in Example3,2-amino-5-chloro-benzoic acid was converted to5-chloro-2-tetrazol-1-yl-benzylamine.

[0172]¹H NMR (CDCl₃, 400 MHz) δ 9.24 (s, 1H), 7.64 (d, 1H, J=2.2 Hz),7.46 (m, 1H), 7.38 (m, 1H), 3.68 (s, 2H).

EXAMPLE 5

[0173] 2-Pyrazol-1-yl-benzylamine Trifluoroacetic Acid Salt

[0174] Step A

[0175] 2-Pyrazol-1-yl-benzoic acid (5-1)

[0176] To a vigorously stirred mixture of 2-hydrazinobenzoic acidhydrochloride (50 g, 0.27 mol) and malonaldehyde bis-dimethylacetal (43ml, 0.27 mol) in water (630 ml) was gradually added conc. HCl (30 ml).The reaction mixture was refluxed for 2 h and methanol was evaporated.The inorganic layer was treated with charcoal until colorless, cooled,left for 2 h and filtered. The residue was washed with cold water anddried in the air to give 2-pyrazol-1-yl-benzoic acid; MS (ES+) M+1 189.4for C₁₀H₈N₂O₂.

[0177] Step B

[0178] 2-Pyrazol-1-yl-benzamide (5-2)

[0179] A solution of 2-pyrazol-1-yl-benzoic acid (50 mg, 0.26 mmol),ammonium chloride (28 mg, 0.52 mmol),1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (100 mg,0.52 mmol), 1-hydroxy-7-azabenzotriazole (71 mg, 0.52 mmol) anddiisopropylethylamine (0.17 ml, 1.0 mmol) in N,N-dimethylformamide (0.75ml) was stirred at room temperature for 5-h. Water was added and thereaction mixture was extracted with ethyl acetate. Drying and solventevaporation gave 2-pyrazol-1-yl-benzamide; ¹H NMR (CD₃OD, 400 MHz) δ7.92 (d, 1H, J=2.4 Hz), 7.70-7.48 (m, 5H), 6.49 (m, 1H).

[0180] Step C

[0181] 2-Pyrazol-1-yl-benzylamine Trifluoroacetic Acid Salt (5-3)

[0182] A solution of 2-pyrazol-1-yl-benzamide (68 mg) andborane-tetrahydrofuran complex (1M solution in tetrahydrofuran, 1.4 ml,1.4 mmol) in tetrahydrofuran (2 ml) was heated at reflux temperature for2h. Hydrochloric acid (1M solution in water, 2.8 ml) was added and thereaction mixture was heated at reflux temperature for 30 minutes. Thesolution was neutralized with 1N sodium hydroxide, concentrated toremove tetrahydrofuran and extracted with chloroform. Drying and solventevaporation gave an oil; purification by reverse phase preparative HPLC(5% to 95% CH₃CN in water containing 0.1% TFA, C18 PRO YMC 20×150 mm)gave 2-pyrazol-1-yl-benzylamine trifluoroacetic acid salt; ¹H NMR(CDCl₃, 400 MHz) δ 8.80 (bs, 2H), 7.80 (m, 2H), 7.62-7.37 (m, 4H), 6.56(t, 1H, J=2.2 Hz), 4.07 (s, 2H).

EXAMPLE 6

[0183] 2-(1H-Imidazol-2-yl)-benzylamine

[0184] Step A

[0185] 2-Cyano-benzimidic Acid Ethyl Ester Hydrochloride (6-1)

[0186] A suspension of phthalonitrile (70 g, 0.55 mol) in ethanol (100ml) and chloroform (200 ml) was warmed and then cooled to 0° C. Thereaction mixture was saturated with HCl (g) and then aged at 0° C. for 2weeks. The resultant precipitate was filtered and washed withchloroform. Dilution of the filtrate with ether produced additional2-cyano-benzimidic acid ethyl ester hydrochloride.

[0187] Step B

[0188] 2-(1H-Imidazol-2-yl)-benzonitrile Hydrochloride (6-2)

[0189] A solution of 2-cyano-benzimidic acid ethyl ester hydrochloride(43 g, 0.20 mol) and 2,2-diethoxy-ethylamine (30 ml, 0.21 mol) inmethanol (430 ml) was aged at room temperature for 1 h. The reactionmixture was concentrated to remove methanol and conc. sulfuric acid (110ml) was added. After heating on a steam bath for 1.5 h, the reactionmixture was diluted with water (700 ml) and extracted with chloroform.The aqueous phase was made strongly basic with sodium hydroxide andextracted with chloroform. Hydrochloric acid (12N) was added to give pH3-4, tar was filtered and the filtrate was concentrated. The resultantbrown solid was sublimed at 200-220° C. The purified solid was dissolvedin hydrochloric acid solution (6N, 110 ml), byproducts filtered and thefiltrate concentrated. The residue was diluted with ethanol (100-120 ml)containing hydrochloric acid (12N, 1 ml), boiled briefly and filtered.Further concentration and cooling of the filtrate gave2-(1H-imidazol-2-yl)benzonitrile hydrochloride (1.5 g). The filtrate wasconcentrated further and diluted with acetone. Filtration gave2-(1H-imidazol-2-yl)-benzoic acid hydrochloride (7.3 g). Dilution of thefiltrate with acetone and filtration of the resultant solid gaveadditional 2-(1H-imidazol-2-yl)-benzonitrile hydrochloride; mp 200-204°C.; IR 4.5 μ.

[0190] Step C

[0191] 2-(1H-Imidazol-2-yl)-benzonitrile (6-3)

[0192] To a solution of 2-(1H-imidazol-2-yl)-benzonitrile hydrochloride(3 g, 0.014 mol) in water (20 ml) was added sodium hydroxide solution(2.5 N, 5 ml). Filtration of the resultant precipitate andrecrystallization from ethyl acetate gave2-(1H-imidazol-2-yl)-benzonitrile; Anal. Calcd. For C₁₀H₇N₃: C, 70.99;H, 4.17; N, 24.84. Found: C, 70.74; H, 4.08; N, 25.24.

[0193] Step D

[0194] 2-(1H-Imidazol-2-yl)-benzylamine (6-4)

[0195] A solution of 2-(1H-imidazol-2-yl)-benzonitrile (50 mg, 0.30mmol) in ethanol saturated with ammonia (5 ml) was stirred in thepresence of Raney nickel (50% slurry in water, washed with ethanol,catalytic amount) under a hydrogen atmosphere for 2 h. The reactionmixture was filtered over celite and concentrated to give2-(1H-imidazol-2-yl)-benzylamine; ¹H NMR (CDCl₃, 400 MHz) δ 8.13 (d, 1H,J=7.5 Hz), 7.42 (m, 1H), 7.28 (m, 2H), 7.18 (bs, 2H), 3.96 (s, 2H).

EXAMPLE 7

[0196] C-(3-[1,2,4]Triazol-1-yl-pyridin-2-yl)-methylamine HydrochlorideSalt

[0197] Step A

[0198] 3-[1,2,4]Triazol-1-yl-pyridine-2-carbonitrile (7-1)

[0199] To a solution of 2-cyano-3-fluoro-pyridine (2.99 g, 24.49 mmol,preparation described in Sakamoto et.al., Chem. Pharm. Bull. 1985,33(2), 565-571) in DMF (30 ml) is added cesium carbonate (2.03 g, 29.39mmol) and 1,2,4-triazole (2.03 g, 29.39 mmol) and the reaction mixtureis stirred at 65° C. for 4 h. After cooling to room temperature, themixture is diluted with water and extracted with EtOAc 3 times. Theaqueous layer is saturated with LiCl and further extracted with EtOAc.The combined organic layer is dried on sodium sulfate, concentrated invacuo. The crude product is purified by flash chromatography (silicagel, 2% MeOH containing 10% NH₄OH in CH₂Cl₂ to 6%) to give3-[1,2,4]triazol-1-yl-pyridine-2-carbonitrile. ¹H NMR (CDCl₃, 400 MHz) δ8.95 (s, 1H); 8.8 (d, J=4 Hz, 1H); 8.24 (s, 1H); 8.22 (d, J=8.5 Hz, 1H);7.75 (dd, J=4, 8.5 Hz, 1H).

[0200] Step B

[0201] (3-[1,2,4]Triazol-1-yl-pyridin-2-ylmethyl)-carbamic acidtert-butyl ester (7-2)

[0202] To a suspension of Raney Nickel (ca. 3 pipets of suspension inwater, washed/decanted with EtOH several times) in MeOH saturated withNH₃ (200 ml) was added 3-[1,2,4]triazol-1-yl-pyridine-2-carbonitrile(3.745 g, 21.88 mmol). The mixture was hydrogenated at 55 Psi for 18 h.The reaction mixture was filtered on celite under a flow of argon andthe filtrate was concentrated in vacuo. To a solution of the crudematerial in CH₂Cl₂ (100 ml) and MeOH (10 ml) was added di-tert-butyldicarbonate (6.2 g, 28.4 mmol) and the reaction mixture was stirred atroom temperature for 30 min. The crude product obtained by concentrationin vacuo is purified by flash chromatography (silica gel, 2% MeOHcontaining 10% NH₄OH in CH₂Cl₂ to 6%) to give(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-carbamic acid tert-butylester. ¹H NMR (CDCl₃, 400 MHz) δ 8.72 (d, J=4.8 Hz, 1H); 8.42 (s, 1H);8.18 (s, 1H); 7.70 (d, J=7.6 Hz, 1H); 7.40 (dd, J=4.8, 7.6 Hz, 1H); 5.85(bs, 1H); 4.43 (d, J=5.4 Hz, 2H); 1.45 (s, 9H).

[0203] Step C

[0204] C-(3-[1,2,4]Triazol-1-yl-pyridin-2-yl)-methylamine HydrochlorideSalt (7-3)

[0205] Through a solution of(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-carbamic acid tert-butylester (4.08 g) in CH₂Cl₂ (100 ml) and MeOH (20 ml) cooled to 0° C. wasbubbled HCl (g) for 10 min. The flask was sealed and the reactionmixture was stirred at room temperature for 18 h. Nitrogen was bubbledthrough the reaction mixture for 5 min and the reaction mixture wasconcentrated to give C-(3[1,2,4]triazol-1-yl-pyridin-2-yl)-methylaminehydrochloride salt as a white solid. ¹H NMR (CD₃OD, 400 MHz) δ 9.67 (s,1H); 8.85 (d, J=5.3 Hz, 1H); 8.72 (s, 1H); 8.18 (d, J=8 Hz, 1H); 7.7(dd, J=5.3, 8 Hz, 1H); 4.45 (s, 2H).

EXAMPLE 8

[0206] 5-Chloro-2-[1.2.4]triazol-1-yl-benzylamine

[0207] Step A

[0208] 5-Chloro-2-[1,2,4]triazol-1-yl-benzonitrile (8-1)

[0209] To a solution of 2,5-dichlorobenzonitrile (10 g, 58.1 mmol) inDMF (100 ml) was added cesium carbonate (22.7 g, 69.8 mmol) and1,2,4-triazole (4.8 g, 69.8 mmol) and the reaction mixture was stirredat 65° C. for 5.5 h, at 75° C. for 16 h, at 85° C. for 7 h. More1,2,4-triazole (5 g) was added and the reaction mixture was stirred at85° C. for 18 h and at 100° C. for 4h. After cooling to roomtemperature, the mixture was diluted with water and extracted with EtOAc3 times. The combined organic layer was washed with aqueous LiCl, driedon sodium sulfate, concentrated in vacuo to give5-chloro-2-[1,2,4]triazol-1-yl-benzonitrile as a white solid which wasused in the next step without further purification.

[0210] Step B

[0211] 5-Chloro-2-[1,2,4]triazol-1-yl-benzylamine (8-2)

[0212] To a suspension of 5-chloro-2-[1,2,4]triazol-1-yl-benzonitrile(11.87 g, 58 mmol) in EtOH saturated with NH₃ (500 ml) was added RaneyNickel (ca. 5 pipets of suspension in water, washed/decanted with EtOHseveral times). The mixture was hydrogenated at 1 atm for 26 h. Thereaction mixture was filtered on celite under a flow of argon and thefiltrate was concentrated in vacuo. The crude product was purified byflash chromatography (silica gel, 5% MeOH containing 10% NH₄OH in CH₂Cl₂to 10%) to give 5-chloro-2-[1,2,4]triazol-1-yl-benzylamine as a whitesolid.

[0213]¹H NMR (CDCl₃, 400 MHz) δ 8.47 (s, 1H); 8.14 (s, 1H); 7.58 (d,J=2.3 Hz, 1H); 7.38 (dd, J=2.3, 7.9 Hz, 1H); 7.30 (d, J=7.9 Hz, 1H);3.70 (s, 2H). 8.72 (d, J=4.8 Hz, 1H); 8.42 (s, 1H); 8.18 (s, 1H); 7.70(d, J=7.6 Hz, 1H); 7.40 (dd, J=4.8, 7.6 Hz, 1H); 5.85 (bs, 1H); 4.43 (d,J=5.4 Hz, 2H); 1.45 (s, 9H).

EXAMPLE 9

[0214] 2-(1,2,4-Triazol-1-yl)benzylamine

[0215] Step A

[0216] 2-(1,2,4-Triazol-1-yl)cyanobenzene (9-1)

[0217] To a stirred solution of 2-fluorocyanobenzene (5.0 g, 41 mmol) inDMF (75 mL) was added 1,2,4-triazole (3.0 g, 43 mmol) and cesiumcarbonate (14 g, 43 mmol). The mixture was warmed to 50° C. and stirredunder inert atmosphere for 18 h. The mixture was cooled to ambienttemperature, diluted with an equal volume of EtOAc, filtered, and thefiltrate solvents were removed under reduced pressure. The residue waspartitioned between ether (50 mL) and water (100 mL). The undissolvedsolid was collected by suction filtration and dried under reducedpressure to give 4.6 g of a 10:1 mixture of2-(1,2,4-triazol-1-yl)cyanobenzene (hplc retention time=2.29 min, 5% to100% CH₃CN in water containing 0.1% TFA, Zorbax C8, 4.6 mm ID×7.5 cm,3.5 micron; TLC Rf=0.6, EtOAc) and 2-(1,2,4-triazol-4-yl)cyanobenzene(hplc retention time=1.91 min, 5% to 100% CH₃CN in water containing 0.1%TFA, Zorbax C8, 4.6 mm ID×7.5 cm, 3.5 micron; TLC Rf=0.1, EtOAc). Themixture was separated by flash chromatography using a gradient elutionof 0:100 to 5:95 MeOH:EtOAc to give 2-(1,2,4-triazol-1-yl)cyanobenzene(¹H NMR (DMSO-d₆) δ 9.19 (s, 1H), 8.37 (s, 1H), 8.10 (d, J=7.6 Hz, 1H),7.96-7.87 (m, 2H), 7.71 (t, J=7.7 Hz, 1H); mass spec m/z=171 (M⁺+H)) and2-(1,2,4-triazol-4-yl)cyanobenzene (¹H NMR (DMSO-d₆) δ 9.03 (s, 2H),8.13 (d, J=7.6 Hz, 1H), 7.93(t, J=7.8 Hz, 1H), 7.80 (d, J=7.8 Hz, 1H),7.74 (t, J=7.7 Hz, 1H); mass spec m/z=171 (M⁺+H)), both as white solids.

[0218] Step B

[0219] 2-(1,2,4-Triazol-1-yl)-benzylamine (9-2)

[0220] A solution of 2-(1,2,4-triazol-1-yl)cyanobenzene (508 mg, 2.99mmol) and 25% by weight of palladium on carbon, 10% catalyst (134 mg) inethanol (75 ml) was placed on a PARR Hydrogenation Apparatus under ahydrogen atmosphere at 55 psi. overnight. The mixture was filteredthrough celite and concentrated to give2-(1,2,4-triazol-1-yl)-benzylamine; ¹H NMR (CD₃OD) δ 8.80 (s, 1H), 8.22(s, 1H), 7.64-7.43 (m, 4H), 3.66 (s, 2H).

EXAMPLE 10

[0221] 2-(1,2,4-Triazol-4-yl)benzylamine

[0222] Step A

[0223] 2-(1,2,4-Triazol-4-yl)benzylamine (10-1)

[0224] 2-(1,2,4-Triazol-4-yl)cyanobenzene (0.3 g; 1.76 mmol) from step Aof example 9 was combined with 30% by weight of palladium on carbon, 10%catalyst (100 mg) in ethanol (75 ml) and placed on a PARR Hydrogenationapparatus under a hydrogen atmosphere at 55 psi. for 48 hours. Themixture was filtered through celite and concentrated to give2-(1,2,4-triazol-4-yl)benzylamine; ¹H NMR (CD₃OD) δ 8.77 (s, 2H),7.69-7.59 (m, 4H), 3.61 (s, 2H).

EXAMPLE 11

[0225] 3-(Tetrazol-1-yl)-2-aminomethylpyridine

[0226] Step A

[0227] 3-(Tetrazol-1-yl)cyanopyridine (11-1)

[0228] To a stirred solution of tetrazole (1.0 g, 14 mmol) in DMF (150mL) was added 40% aqueous tetrabutylammonium hydroxide (7.8 g, 12 mmol).The solvent was removed under reduced pressure. To ensure removal of allthe water from the tetrabutylammonium hydroxide solution, the residuewas redissolved in DMF and the solution was evaporated under reducedpressure. This procedure was repeated a total of three times. Theresidue was then dissolved in DMF (60 mL) and 2-cyano-3-fluoro-pyridine(1.5 g, 12 mmol, preparation described in Sakamoto et.al., Chem. Pharm.Bull. 1985, 33(2), 565-571) was added. The reaction was stirred atambient temperature under inert atmosphere for four days, at which timehplc analysis indicated about 65% conversion of the3-fluoro-2-cyanopyridine to new products. The solvent was removed underreduced pressure and the residue was partitioned between EtOAc andwater. The EtOAc layer was separated, dried over anhydrous MgSO₄, andfiltered. The solvent was removed under reduced pressure and the residuewas purified by flash chromatography using a gradient elution of 1:4 to100:0 EtOAc:hexanes to give 3-(tetrazol-1-yl)cyanopyridine as a whitecrystalline solid (TLC Rf=0.5, 1:1 EtOAc-hexanes; hplc retentiontime=2.04 min, 5% to 100% CH₃CN in water containing 0.1% TFA, Zorbax C8,4.6 mm ID×7.5 cm, 3.5 micron);

[0229]¹H NMR (CDCl₃) δ 9.42 (s, 1H), 8.94 (dd, J=1.3, 4.6 Hz, 1H), 8.31(dd, J=1.3, 8.4 Hz, 1H), 7.87 (dd, J=4.6, 8.4 Hz, 1H).

[0230] Step B

[0231] 3-(Tetrazol-1-yl)-2-aminomethylpyridine (11-2)

[0232] A solution of 3-(tetrazol-1-yl)cyanopyridine (250 mg, 1.45 mmol)and 45% by weight of palladium on carbon, 10% catalyst (110 mg) inethanol (75 ml) was placed on a PARR Hydrogenation Apparatus under ahydrogen atmosphere at 55 psi. overnight. The mixture was filteredthrough celite and concentrated to give3-(tetrazol-1-yl)-2-aminomethylpyridine; ¹H NMR (CD₃OD) δ 9.60 (s, 1H),8.83-8.81 (m, 1H), 7.99-7.97 (m, 1H), 7.59-7.56 (m, 1H), 3.77 (s, 2H).

EXAMPLE 12

[0233] 2-(1H-Pyrazol-3-yl)-benzylamine Hydrochloride Salt

[0234] Step A

[0235] 1-(Tetrahydro-pyran-2-yl)-1H-pyrazole (12-1)

[0236] To pyrazole (14.3 g, 0.21 mol) was added 3,4-dihydro-2H-pyran (29ml, 0.315 mol) and, after complete dissolving, trifluoroacetic acid (0.1ml, 0.0013 mol) was added to the obtained solution. The reaction mixturewas refluxed for 5 h, sodium hydride (0.2 g, 0.008 mol) was added, andthe mixture was distilled to give 1-(tetrahydro-pyran-2-yl)-1H-pyrazole;b.p. ˜60-65° C./0.5-1 torr.

[0237] Step B

[0238] 1H-Pyrazol-3-ylboronic Acid (12-2)

[0239] To a solution of 1-(tetrahydro-pyran-2-yl)-1H-pyrazole (7.61 g,0.0525 mol) in dry THF (50 ml), a 1.6M hexane solution of BuLi (33 ml)was added dropwise at −70° C. A white bulky precipitate formedimmediately. Triisopropyl borate (12.7 ml, 0.055 mol) was added over 10min at the same temperature (−70° C.), and kept at this temperature for1 h. Then the mixture was decomposed with 2 eq. of 2M HCl underintensive stirring to give a white bulky precipitate. Duringdecomposition, the temperature rose from −70° C. to 20° C. Theprecipitate was filtered off, washed with water and benzene (until thedisappearance of a typical smell) to give 1H-pyrazol-3-ylboronic acid;¹H NMR (D20) δ 7.47 (d, 1H), 6.20 (d, 1H).

[0240] Step C

[0241] Tert-Butyl-2-bromobenzylcarbamate (12-3)

[0242] To a solution of 2-bromobenzylamine hydrochloride (11.12 g, 0.05mol) in dimethylformamide (50 ml) was added di-tert-butyl dicarbonate(10.91 g, 0.05 mol) and triethylamine (3.66 ml, 0.05 mol). The reactionmixture was stirred at room temperature overnight. Saturated sodiumcarbonate solution was added and the mixture was extracted with ethylacetate. The combined organic layers were washed with brine. Drying andsolvent evaporation gave tert-butyl-2-bromobenzylcarbamate; MS (ES+) M+1286.4 for C₁₂H₁₆BrNO₂.

[0243] Step D

[0244] Tert-Butyl-2-(1H-pyrazol-3-yl)benzylcarbamate (12-4)

[0245] To a solution of 1H-pyrazol-3-ylboronic acid (156 mg, 1.4 mmol),tetrakis(triphenylphosphine)palladium(0) (242 mg, 0.21 mmol), and sodiumcarbonate (222 mg, 2.1 mmol) in dimethylformamide (2 ml), was addedtert-butyl-2-bromobenzylcarbamate (200 mg, 0.699 mmol). The suspensionwas stirred at 100° C. for 2h, cooled to room temperature, poured ontosaturated sodium bicarbonate and extracted with ethyl acetate. Thecombined organic layers were washed with saturated sodium chloride,dried with magnesium sulfate and concentrated in vacuo. The crudematerial was passed through silica (ISCO, 0-30% ethyl acetate/hexane) togive tert-butyl 2-(1H-pyrazol-3-yl)benzylcarbarnate; MS (ES+) M+1 274.1for C₁₅H₁₉N₃O₂.

[0246] Step E

[0247] 2-(1H-Pyrazol-3-yl)-benzylamine Hydrochloride Salt (12-5)

[0248] Hydrogen chloride gas was bubbled through a 0° C. solution oftert-butyl 2-(1H-pyrazol-3-yl)benzylcarbamate (60 mg, 0.220 mmol) inethyl acetate (5 ml) for 2 min and stirred for 40 min. A precipitateformed, and the suspension was concentrated in vacuo to give2-(1H-pyrazol-3-yl)-benzylamine hydrochloride salt; MS (ES+) M+1 174.1for C₁₀H₁₁N₃.

EXAMPLE 13

[0249] 2-Imidazol-1-yl-benzylamine

[0250] Step A

[0251] 2-Imidazol-1-yl-benzonitrile (13-1)

[0252] To a solution of 1H-imidazole (0.61 g, 9.0 mmol) indimethylformamide (8 ml) was added sodium hydride (60% in oil, 0.36 g,9.0 mmol) and the reaction mixture was stirred at room temperature for40 min. 2-Fluoro-benzonitrile (0.9 ml, 8.2 mmol) was added and thereaction was stirred at room temperature for 45 min, heated to 60° C.for 45 min and then stirred at room temperature overnight. Ethyl acetatewas added and the mixture was washed with water and brine. Drying andsolvent evaporation gave 2-imidazol-1-yl-benzonitrile; ¹H NMR (CDCl₃,400 MHz) δ 7.86 (bs, 1H), 7.84 (m, 1H), 7.75 (m, 1H), 7.54 (m, 1H), 7.47(dd, 1H, J=8.1 Hz, J=1 Hz), 7.36 (m, 1H), 7.27 (m, 1H).

[0253] Step B

[0254] 2-Imidazol-1-yl-benzylamine (13-2)

[0255] A solution of 2-imidazol-1-yl-benzonitrile (200 mg, 1.2 mmol) inethanol saturated with ammonia (20 ml) was stirred in the presence ofRaney nickel (50% slurry in water, washed with ethanol, catalyticamount) under a hydrogen atmosphere for 4 h. The reaction mixture wasfiltered over celite and concentrated to give2-Imidazol-1-yl-benzylamine; ¹H NMR (CDCl₃, 400 MHz) δ 7.69 (bs, 1H),7.57 (m, 1H), 7.47 (m, 1H), 7.38 (m, 1H), 7.27 (m, 1H), 7.22 (bs, 1H),7.16 (m, 1H), 3.73 (s, 2H).

EXAMPLE 14

[0256] 2-(1H-Tetrazol-5-yl)-benzylamine Hydrochloride Salt

[0257] Step A

[0258] 2-Azidomethyl-benzonitrile (14-1)

[0259] A solution of 2-bromomethyl-benzonitrile (1.0 g, 5.1 mmol) andsodium azide (0.40 g, 6.1 mmol) in dimethylformamide (10 ml) was stirredat room temperature for 2 h. Ethyl acetate was added and the reactionmixture was washed with water and brine. Drying and solvent evaporationgave 2-azidomethyl-benzonitrile; ¹H NMR (CDCl₃, 400 MHz) δ 7.71 (d, 1H,J=7.7 Hz), 7.64 (m, 1H), 7.53 (d, 1H, J=7.8 Hz), 7.47 (t, 1H, J=7.6 Hz),4.62 (s, 2H).

[0260] Step B

[0261] (2-Cyano-benzyl)-carbamic Acid tert-butyl Ester (14-2)

[0262] A solution of 2-azidomethyl-benzonitrile (0.59 g, 3.7 mmol), tin(II) chloride (1.0 g, 5.5 mmol) and di-tert-butyl dicarbonate (1.2 g,5.5 mmol) in methanol (16 ml) and tetrahydrofuran (8 ml) was stirred atroom temperature for 1 h. Concentration and flash chromatography (silicagel, hexane-ethyl acetate, 85:15) gave (2-cyano-benzyl)-carbamic acidtert-butyl ester; ¹H NMR (CDCl₃, 400 MHz) δ 7.64 (d, 1H, J=7.8 Hz), 7.58(m, 1H), 7.52 (m, 1H), 7.37 (m, 1H), 5.12 (bs, 1H), 4.50 (d, 2H, J=6Hz), 1.45 (s, 9H).

[0263] Step C

[0264] [2-(1H-Tetrazol-5-yl)-benzyl]-carbamic Acid Tert-Butyl Ester(14-3)

[0265] A solution of (2-cyano-benzyl)-carbamic acid tert-butyl ester (35mg, 0.15 mmol), sodium azide (49 mg, 0.75 mmol), ammonium chloride (40mg, 0.75 mmol) in dimethylformamide (0.5 ml) was heated to 110° C. for 8h. After cooling to room temperature, ethyl acetate was added and theresultant solid filtered. Concentration of the filtrate gave[2-(1H-tetrazol-5-yl)-benzyl]-carbamic acid tert-butyl ester; ¹H NMR(CD₃OD, 400 MHz) δ 7.71(d, 1H, J=7.5 Hz), 7.58 (m, 2H), 7.48 (m, 1H),4.44 (s, 2H), 1.42 (s, 9H).

[0266] Step D

[0267] 2-(1H-Tetrazol-5-yl)-benzylamine Hydrochloride Salt (14-4)

[0268] Through a solution of [2-(1H-tetrazol-5-yl)-benzyl]-carbamic acidtert-butyl ester (33 mg) in ethyl acetate (15 ml), cooled to 0° C. wasbubbled HCl (g) for 5 min. The reaction was stirred at room temperaturefor 0.5 h. Nitrogen was bubbled through the reaction mixture and etherwas added. Filtration gave 2-(1H-tetrazol-5-yl)-benzylaminehydrochloride salt; ¹H NMR (CD₃OD, 400 MHz) δ 7.86 (d, 1H, J=7.7 Hz),7.79 (m, 1H), 7.69 (m, 1H), 7.63 (m, 1H), 4.36 (s, 2H).

EXAMPLE 15

[0269] 2-(1-Methyl-1H-tetrazol-5-yl)-benzylamine Hydrochloride Salt

[0270] Step A

[0271] [2-(1-Methyl-1H-tetrazol-5-yl)-benzyl]-carbamic Acid Tert-ButylEster (15-1)

[0272] A solution of [2-(1H-tetrazol-5-yl)-benzyl]-carbamic acidtert-butyl ester (0.23 g, 0.84 mmol, preparation described in example14, Step C), crushed potassium carbonate (0.58 g, 4.2 mmol) andiodomethane (0.26 ml, 4.2 mmol) in dimethylformamide (4.7 ml) wasstirred at room temperature for 1 h. Water was added and the reactionmixture was extracted with chloroform. Drying and solvent evaporationgave a mixture of regioisomers; separation and purification by reversephase preparative HPLC (5% to 95% CH₃CN in water containing 0.1% TFA,C18 PRO YMC 20×150 mm) gave[2-(1-methyl-1H-tetrazol-5-yl)-benzyl]-carbamic acid tert-butyl ester;¹H NMR (CDCl₃, 400 MHz) δ 7.66 (d, 1H, J=7.4 Hz), 7.58 (m, 1H), 7.46 (m,1H), 7.33 (d, 1H, J=7.6 Hz), 4.17 (d, 2H, J=6.3 Hz), 4.05 (s, 3H), 1.41(s, 9H) and [2-(2-methyl-2H-tetrazol-5-yl)-benzyl]-carbamic acidtert-butyl ester; ¹H NMR (CDCl₃, 400 MHz) δ 8.06 (d, 1H, J=7.4 Hz), 7.61(d, 1H, J=7 Hz), 7.44 (m, 2H), 5.82 (bs, 1H), 4.52 (d, 2H, J=6.5 Hz),4.44 (s, 3H), 1.43 (s, 9H).

[0273] Step B

[0274] 2-(1-Methyl-1H-tetrazol-5-yl)-benzylamine Hydrochloride Salt(15-2)

[0275] Through a solution of[2-(1-methyl-1H-tetrazol-5-yl)-benzyl]-carbamic acid tert-butyl ester(10 mg) in ethyl acetate (5 ml), cooled to 0° C. was bubbled HCl (g) for5 min. The reaction was stirred at room temperature for 0.5 h. Nitrogenwas bubbled through the reaction mixture. Concentration from ethylacetate gave 2-(1-methyl-1H-tetrazol-5-yl)-benzylamine hydrochloridesalt; ¹H NMR (CD₃OD, 400 MHz) δ 7.75 (m, 4H), 4.18 (s, 3H), 4.11 (m,2H).

EXAMPLE 16

[0276] 2-(2-Methyl-2H-tetrazol-5-yl)-benzylamine Hydrochloride Salt

[0277] Step A

[0278] 2-(2-Methyl-2H-tetrazol-5-yl)-benzylamine Hydrochloride Salt(16-1)

[0279] Through a solution of[2-(2-methyl-2H-tetrazol-5-yl)-benzyl]-carbamic acid tert-butyl ester(15 mg, preparation described in example 15, Step A) in ethyl acetate (5ml), cooled to 0° C. was bubbled HCl (g) for 5 min. The reaction wasstirred at room temperature for 0.5 h. Nitrogen was bubbled through thereaction mixture. Concentration from ethyl acetate gave2-(2-methyl-2H-tetrazol-5-yl)-benzylamine hydrochloride salt; ¹H NMR(CD₃OD, 400 MHz) δ 8.24 (m, 1H), 7.63 (m, 3H) 4.48 (s, 3H), 4.47 (m,2H).

EXAMPLE 17

[0280][6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid

[0281] Step A

[0282] Oxo-pyridin-2-yl-acetic Acid Ethyl Ester (17-1)

[0283] To a stirred solution of 20 mL (210 mmol) of 2-bromopyridine in500 mL of dry ether at −78° C. under Ar was added 85 mL of a 2.5 Msolution of n-butyllithium in hexane in a slow stream. After stirring inthe cold for 30 min, the solution was transferred over a 5 min periodvia two cannula into a 0° C. stirred solution of 100 mL (736 mmol) ofdiethyl oxalate in 1.0 L of dry ether under Ar. After stirring for 2h inthe cold, the reaction mixture was washed with 600 mL of sat. NaHCO₃,water, and brine. The solution was dried over MgSO₄ and the solventsconcentrated at reduced pressure to give a red oil that was purified bySiO₂ chromatography (10×15 cm) using 1:4 to 35:65 EtOAc-hexanes. Theproduct-containing fractions were concentrated at reduced pressure toafford the product as a reddish oil: ¹H NMR (CDCl₃) δ 1.42 (t, 3H),4.45-4.55 (m, 2H), 7.55-7.6 (m, 1H), 7.9-7.95 (m, 1H), 8.11 (d, 1H),8.78 (d, 1H).

[0284] Step B

[0285] Difluoro-pyridin-2-yl-acetic Acid Ethyl Ester (17-2)

[0286] A stirred solution of 22 g (123 mmol) of oxo-pyridin-2-yl-aceticacid ethyl ester and 75 g (465 mmol) of diethylaminosulfurtrifluoride(DAST) were heated to 55° C. under Ar overnight. Because the reactionwas not complete, 5 g additional DAST was added, and the reaction heatedfor an additional 24 h. The reaction mixture was cooled to rt, andpoured very slowly into a stirred mixture of 1 kg of ice, 400 mL ofethyl acetate and 500 mL of sat. NaHCO₃. After the addition, the mixturewas basified by the addition of solid NaHCO₃. The aqueous layer wasextracted with EtOAc, and the combined organic layers washed with sat.NaHCO₃, brine, dried over Na₂SO₄ and the solvents concentrated atreduced pressure to give the product as a brown oil: ¹H NMR (CDCl₃) δ1.35 (t, 3H), 4.35-4.4 (m, 2H), 7.4-7.45 (m, 1H), 7.75 (d, 1H), 7.95 (d,1H), 8.45 (d, 1H).

[0287] Step C

[0288] 2,2-Difluoro-2-pyridin-2-yl-ethanol (17-3)

[0289] To a stirred solution of 19.5 g (97 mmol) ofdifluoro-pyridin-2-yl-acetic acid ethyl ester in 200 mL of absoluteethanol at 0° C. was added 4.42 g (116 mmol) of sodium borohydride insmall portions. After 30 min, the reaction was quenched by the additionof 50 mL of sat. NH₄Cl. The reaction mixture was concentrated at reducedpressure and the residue partitioned between 500 mL of ethyl acetate andsat. NaHCO₃. The organic layer was washed with water, brine, and driedover Na₂SO₄ and concentrated at reduced pressure to give a brown oilthat was purified on SiO₂ (10×17 cm) using 1:1 EtOAc-hexane. Afterre-chromatographing the mixed fractions, all clean fractions werecombined and concentrated at reduced pressure, giving the product as abeige crystalline solid: ¹H NMR (CDCl₃) δ 3.6 (t, 1H), 4.17-4.3 (m, 2H),7.4-7.45 (m, 1H), 7.73 (d, 1H), 7.84-7.91 (m, 1H), 8.61 (d, 1H).

[0290] Step D

[0291] Trifluoro-methanesulfonic acid 2,2-difluoro-2-pyridin-2-yl-ethylester (17-4)

[0292] To a stirred solution of 5 g (31.4 mmol) of2,2-difluoro-2-pyridin-2-yl-ethanol and 9.69 g (47.2 mmol) of2,6-di-t-butyl-4-methylpyridine in 110 mL of methylene chloride at −78°C. under Ar was added 7.93 mL (47.2 mmol) of triflic anhydride dropwise.After 1 h, the reaction was diluted with 100 mL of pentane and filtered.The filtrate was concentrated and treated again with pentane andfiltered. Concentration of the filtrate gave the product as a brown oil,contaminated with 2,6-di-t-butyl-4-methylpyridine: ¹H NMR (CDCl₃) δ 5.12(t, 2H), 7.45-7.5 (m, 1H), 7.75° (d, 1H), 7.86-7.94 (m, 1H), 8.65 (d,1H).

[0293] Step E

[0294] 2-(2-Azido-1,1-difluoro-ethyl)-pyridine (17-5)

[0295] To a stirred solution of 5.5 g of trifluoro-methanesulfonic acid2,2-difluoro-2-pyridin-2-yl-ethyl ester 1-4 in 70 mL of DMF was added6.74 g (104 mmol) of sodium azide under Ar. The mixture was heated to60° C. overnight. A second batch was run in the same manner, and aftercooling to rt, both reactions were poured into 600 mL of water, andextracted with 3×500 mL of ether. The combined extracts were washed withbrine, dried over Na₂SO₄ and concentrated at reduced pressure to give anoil that was purified by SiO₂ (10×6 cm) using hexane 1:3 EtOAc-hexaneand 1:1 EtOAc-hexane. The product-containing fractions were concentratedat reduced pressure to give the product as a yellow oil: ¹H NMR (CDCl₃)δ 4.05 (t, 2H), 7.4-7.45 (m, 1H), 7.73 (d, 1H), 7.83-7.89 (m, 1H), 8.67(d, 1H).

[0296] Step F

[0297] 2,2-Difluoro-2-pyridin-2-yl-ethylamine (17-6)

[0298] A stirred solution of 100 mg of2-(2-azido-1,1-difluoro-ethyl)-pyridine was hydrogenated in 10 mL ofethyl acetate over 100 mg of 10% palladium on carbon using a balloon for1 h. The catalyst was removed by filtration and the solvents removed atreduced pressure. A total of 1.8 g (9.7 mmol) of the azide was reducedusing this procedure to give 2,2-difluoro-2-pyridin-2-yl-ethylamine as ayellow oil: ¹H NMR (CDCl₃) δ 8.66 (d, 1H, 4.2 Hz), 7.82 (td,1H, 7.7, 1.7Hz), 7.68 (d, 1H, 8.1 Hz), 7.37-7.40 (m, 1H), 3.44 (t, 2H, 14.3 Hz),1.41 (br s, 2H).

[0299] Step G

[0300] N-Ethoxycarbonylmethyl-oxalamic Acid Ethyl Ester (17-7)

[0301] To a suspension of ethyl glycine.HCl (38.4 g, 275 mmol) in1,2-dichloroethane (360 mL) was added triethylamine (77.0 mL, 550 mmol)at room temperature. After stirring for 30 minutes the heterogenousmixture was cooled to 0° C. and ethyl oxalyl chloride (30.3 mL, 275 mol)was added dropwise over the course of 1 h. Upon completion of theaddition, the cooling bath was removed and the reaction was stirred atroom temperature overnight. The reaction was diluted with water (250 mL)and the layers separated. The aqueous layer was backwashed with 2portions of dichloromethane (250 mL). The combined organic layers werewashed with water (250 mL), followed by brine (250 mL), dried over MgSO₄and concentrated to give N-ethoxycarbonylmethyl-oxalamic acid ethylester as an oil that was taken directly onto the next step.

[0302] Step H

[0303] [(2,2-Dimethoxy-ethylaminooxalyl)-amino]-acetic Acid Ethyl Ester(17-8)

[0304] To a solution of N-ethoxycarbonylmethyl-oxalamic acid ethyl ester(84.0 g, 414 mmol) 2-1 in 2-propanol (500 mL) was addedaminoacetaldehyde dimethyl acetal (45.7 g, 435 mmol) in one portion.After stirring overnight at room temperature, the reaction mixture wasconcentrated to a thick orange oil. This thick slurry was diluted with2-propanol (300 mL) and the solid was broken up with a spatula.Filtration afforded a solid which was further rinsed with an additionalportion of 2-propanol. Removal of residual 2-propanol was accomplishedvia high vacuum to afford a light orange solid: ¹H NMR (CDCl₃) δ 7.82(br s, 1H), 7.50 (br s, 1H), 4.41 (t, 1H, 5.3 Hz), 4.24 (q, 2H, 7.1 Hz),4.09 (d, 2H, 5.9 Hz), 3.47 (dd, 2H, 5.3, 6.2 Hz), 3.40 (s, 6H), 1.30 (t,3H, 7.1 Hz).

[0305] Step I

[0306] (2,3-Dioxo-3,4-dihydro-2H-pyrazin-1-yl)-acetic Acid Ethyl Ester(17-9)

[0307] A solution of [(2,2-Dimethoxy-ethylanminooxalyl)-amino]-aceticacid ethyl ester (89.8 g, 343 mmol), acetic acid (400 mL), and conc. HCl(2 mL) was heated to reflux. After 1 h the black reaction wasconcentrated to a thick oil (high vacuum employed to ensure completeremoval of AcOH) which was diluted with EtOH (150 mL) and MeOH (150 mL).Scraping the thick black oil with a spatula induced precipitation of theproduct. The MeOH was removed via rotary evaporation and the remainingslurry was filtered and rinsed with EtOH (200 mL) to deliver a tansolid. Recrystallization from refluxing EtOH (300 mL) afforded theproduct as an off-white powder: ¹H NMR (CD₃OD) δ 6.50 (d, 1H, 5.9 Hz),6.36 (d, 1H, 5.9 Hz), 4.58 (s, 2H), 4.23 (q, 2H, 7.1 Hz), 1.28 (t, 3H,7.1 Hz). Further crude dione could be obtained upon concentration of themother liquor.

[0308] Step J

[0309] (3-Bromo-2-oxo-2H-pyrazin-1-yl)-acetic Acid Ethyl Ester (17-10)

[0310] A solution of (2,3-dioxo-3,4-dihydro-2H-pyrazin-1-yl)-acetic acidethyl ester (25.0 g, 126 mmol) and phosphorous oxybromide (37.9 g, 132mmol) in 1,2-dichloroethane (250 mL) was heated to reflux. After 8 h thereaction mixture was treated with sat. aq. Na₂CO₃ (250 mL) and stirredfor 1 h. The mixture was diluted with water (100 mL) and dichloromethane(100 mL), the layers were separated and the aqueous layer was backwashedwith EtOAc (3×200 mL). The combined organics were dried (MgSO₄), andconcentrated to give an oil which was stored on a high vacuum lineovernight to afford a brown solid. ¹H NMR (CDCl₃) δ 7.17 (d, 1H, 4.2Hz), 7.07 (d, 1H, 4.2 Hz), 4.65 (s, 2H), 4.27 (q, 2H, 7.2 Hz), 1.31 (t,3H, 7.2 Hz).

[0311] Step K

[0312][3-(2.2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl Ester (17-11)

[0313] A solution of 4.80 g (30.4 mmol) of2,2-difluoro-2-pyridin-2-yl-ethylamine, 4.24 mL (30.4 mmol) oftriethylamine and 7.93 g (30.4 mmol) of(3-bromo-2-oxo-2H-pyrazin-1-yl)-acetic acid ethyl ester was heated to120° C. in a sealed tube overnight in 12 mL of toluene and 4 mL ofethanol. The reaction was concentrated and the residue was partitionedbetween dichloromethane and sat. aq. NaHCO₃. The aqueous layer wasbackwashed with 4 portions of dichloromethane. The combined organiclayers were dried over MgSO₄ and the solvents removed at reducedpressure to give an oil that was chromatographed on SiO₂ using 60:40 to40:60 hexane-EtOAc to give Ethyl3-(2,2-difluoro-2-(2-pyridylethylamino)pyrazin(1H)-2-one-1-acetate as ayellow solid:

[0314]¹H NMR (CDCl₃) δ 8.67 (dd, 1H, 4.8, 0.7 Hz), 7.81 (ddd,1H, 7.8,7.8, 1.7 Hz), 7.69 (dd, 1H, 7.8, 1 Hz), 7.38 (dd, 1H, 5.1, 7.0 Hz), 6.86(d, 1H, 4.8 Hz), 6.54 (br t, 1H, 5.9 Hz), 6.40 (d, 1H, 4.6 Hz), 4.54 (s,2H), 4.38 (td, 2H, 14.0, 6.4 Hz), 4.24 (q, 2H, 7.1 Hz), 1.29 (t, 3H, 7.1Hz).

[0315] Step L

[0316][6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid Ethyl Ester (17-12)

[0317] A stirred solution of 6.81 g (20.1 mmol) of[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester and 2.42 g (18.1 mmol) of N-chlorosuccinimide in 100 mLof 1,2-dichloroethane was heated to reflux. An additional 242 mg (1.81mmol) and 75 mg (0.56 mmol) of NCS were added to the reaction mixtureafter 1 h and 1.5 h, respectively. After 2.5 h total, the solution wascooled to room temperature and partitioned between dichloromethane (150mL) and sat. aq. NaHCO₃ (200 mL). The layers were separated and theaqueous phase was backwashed with dichloromethane (2×200 mL). Thecombined organic layers were dried over MgSO₄ and the solutionconcentrated to a volume of 10 mL. This liquid was directly loaded ontoa SiO₂ column and eluted with 65:35 to 55:45 hexane-EtOAc to give thetitle compound as a yellow solid: ¹H NMR (CDCl₃) δ 8.68 (d, 1H, 4.8,Hz), 7.83 (ddd,1H, 7.7, 7.7, 1.6 Hz), 7.9 (dd, 1H, 7.9 Hz), 7.40 (dd,1H, 4.9, 7.3 Hz), 6.96 (s, 1H), 6.49 (br t, 1H, 5.9 Hz), 4.89 (s, 2H),4.38 (td, 2H, 13.9, 6.5 Hz), 4.26 (q, 2H, 7.1 Hz), 1.30 (t, 3H, 7.1 Hz).

[0318] Step M

[0319][6-Chloro-3-(2.2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin1-yl]-acetic Acid (17-13)

[0320] To a stirred solution of 7.27 g (19.5 mmol) of[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester in 200 mL of methanol was added 39 mL (39.0 mmol) of 1Maq. potassium hydroxide. After 3 h the solution was acidified to pH=7using conc. HCl, and concentrated at reduced pressure (azeotrope withPhCH₃) to give a white solid containing potassium chloride and theproduct. ¹H NMR (CD₃OD) δ 8.64 (d, 1H, 4.8 Hz), 7.93 (ddd,1H, 7.7, 7.7,1.5 Hz), 7.70 (d, 1H, 8.0 Hz), 7.49 (dd, 1H, 5.2, 7.4 Hz), 6.80 (s, 1H),4.67 (s, 2H), 4.27 (t, 2H, 13.9 Hz).

EXAMPLE 18

[0321]{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid

[0322] Step A

[0323] 2-(2-Azido-1,1-difluoro-ethyl)-pyridine-1-oxide (18-1)

[0324] To a stirred solution of 2-(2-azido-1,1-difluoro-ethyl)-pyridine(5.75 g, 31.3 mmol, preparation described in example 17, step E) in1,2-dichloroethane (100 mL) was added 3-chloroperoxybenzoic acid (10.26g, 41.6 mmol) and 3-tert-butyl-4-hydroxy-5methylphenyl sulfide (1.12 g,3.13 mmol) under Ar. The mixture was heated at 55° C. overnight. In themorning, the solution was poured into a sat. aq. NaHCO₃/Na₂S₂O₃ solution(200 mL). The layers were separated and the aqueous phase was backwashedwith dichloromethane (3×150 mL). The combined organic layers were driedover MgSO₄, concentrated and chromatographed on a short SiO₂ columnusing 100% EtOAc to give the title compound as a white solid: ¹H NMR(CDCl₃) δ 4.38 (t, 2H, 13.5 Hz), 7.36-7.44 (m, 2H), 7.72 (dd, 1H, 2.3Hz, 7.6 Hz), 8.26 (d, 1H, 6.1 Hz).

[0325] Step B

[0326] 2,2-Difluoro-2-(1-oxy-pyridin-2-yl)-ethylamine (18-2)

[0327] Triphenylphosphine (7.72 g, 29.5 mmol) was added to a water bathcooled solution of 2-(2-azido-1,1-difluoro-ethyl)-pyridine-1-oxide (5.61g, 28.1 mmol) in THF (90 mL). After 1 h water (10 mL) was added and themixture was heated to 55° C. Two hours after the addition of water, theheating bath was removed and the solution was allowed to stir overnight.The reaction was subsequently concentrated, diluted with EtOAc (250 mL),and HCl (25 mL, 2.6M in EtOAc) was added dropwise. Stirring wascontinued for 20 min, after which time the mixture was filtered andrinsed with EtOAc (150 mL). To a stirred suspension of this solid indichloromethane (300 mL) was added NaOH (3.33 g in 15 mL H₂O) dropwise.After 15 min the mixture was poured into a separatory funnel and theorganic phase was separated. The aqueous phase was saturated with solidNaCl and extracted with CH₂Cl₂ (3×100 mL). The combined organic extractswere dried over Na₂SO₄ and concentrated to an oil which solidified uponstorage in the freezer: ¹H NMR (CDCl₃) δ 8.25 (br d, 1H, 6.2 Hz), 7.69(dd, 1H, 2.8, 7.3 Hz), 7.32-7.39 (m, 2H), 3.76 (t, 2H, 15.2 Hz), 1.29(br s, 2H).

[0328] Step C

[0329]{3-[2,2-Difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid Ethyl Ester (18-3)

[0330] A mixture of 3.0 g (17.2 mmol) of2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamine, 2.72 mL (19.5 mmol) oftriethylamine and 4.5 g (17.2 mmol) of(3-bromo-2-oxo-2H-pyrazin-1-yl)-acetic acid ethyl ester in 9 mL oftoluene and 3 mL of ethanol was heated to 120° C. in a sealed tube for24 h. The reaction was concentrated and the residue was partitionedbetween EtOAc (200 mL) and sat. aq. NaHCO₃ (200 mL). The aqueous layerwas backwashed with EtOAc (5×150 mL). The combined organic layers weredried over MgSO₄ and the solvents removed at reduced pressure to give abrown solid. This crude material was diluted with EtOAc (50 mL),filtered, and rinsed with EtOAc (2×50 mL) to afford the title compoundas a tan powder: ¹H NMR (CDCl₃) δ 8.26 (d, 1H, 6.4 Hz), 7.61 (br d, 1H,7.9 Hz), 7.34 (dd, 1H, 6.6, 6.6 Hz), 7.26 (dd, 1H), 6.78 (d, 1H, 4.6Hz), 6.39 (br t, 1H, 6.6 Hz), 6.37 (d, 1H, 4.6 Hz), 4.66 (td, 2H, 13.8,7.0 Hz), 4.52 (s, 2H), 4.23 (q, 2H, 7.1 Hz), 1.28 (t, 3H, 7.1 Hz).

[0331] Step D

[0332]{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid Ethyl Ester (18-4)

[0333] A stirred solution of 4.96 g (14.0 mmol) of{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester and 1.86 g (14.0 mmol) of N-chlorosuccinimide in 200 mLof 1,2-dichloroethane was heated to 70° C. After 3 h the solution wascooled to room temperature and partitioned between dichloromethane (150mL) and sat. aq. NaHCO₃ (200 mL). The layers were separated and theaqueous phase was backwashed with dichloromethane (4×200 mL) and EtOAc(2×200 mL). The combined organic layers were dried over NaSO₄ and thesolution concentrated. This crude solid was purified on a SiO₂ columnwith 100% EtOAc to 10:90 MeOH:EtOAc to give the title compound as awhite solid: ¹H NMR (CDCl₃) δ 8.26 (d, 1H, 6.4 Hz), 7.62 (dd, 1H, 2.2,7.9 Hz), 7.35 (ddd, 1H, 2.1, 7.7, 7.7 Hz), 7.2 (dd, 1H, 7.7 Hz), 6.86(s, 1H), 6.35 (br t, 1H, 6.7 Hz), 4.85 (s, 2H), 4.64 (td, 2H, 13.8, 6.9Hz), 4.24 (q, 2H, 7.1 Hz), 1.29 (t, 3H, 7.1 Hz).

[0334] Step E

[0335]{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid (18-5)

[0336] To a stirred solution of 4.88 g (12.6 mmol) of{6-Chloro-3-[2,2-difluoro-2-(1-oxypyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-acetic acid ethyl ester in methanol (100 mL) was added 5.0 g potassiumhydroxide (89.1 mmol dissolved in 20 mL water). After 1 h the solutionwas concentrated, diluted with 50 mL of water and acidified to pH=7using conc. HCl. Concentration at reduced pressure (azeotrope withPhCH₃) afforded an off-white solid containing potassium chloride and thetitle compound: ¹H NMR (CD₃OD) δ 8.36 (d, 1H, 6.2 Hz), 7.69 (dd, 1H,7.7, 2.2 Hz), 7.51-7.59 (m, 2H), 6.67 (s, 1H), 4.62 (s, 2H), 4.55 (t,2H, 13.1 Hz).

EXAMPLE 19

[0337][3-(2,2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticAcid

[0338] Step A

[0339]3-(2,2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticAcid (19-1)

[0340] To a solution of 2.84 g (8.41 mmol)[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester (preparation described in example 17, step K) in 10.0mL methanol was added 8.83 mL (8.83 mmol) 1.0N lithium hydroxide (aq)and the light yellow solution stirred 1 h at room temperature. Thereaction pH was adjusted to 7.0 with a dropwise addition of 1.0N HCl inether to give a precipitate. The solid was removed by filtration, washedwell with water and dried under high vacuum for 24 h to give3-[2,2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticacid as a white solid: ¹H NMR (DMSO-d₆, 400 MHz): δ 13.13 (br s, 1H),8.70 (d, 1H, J=4.7 Hz), 7.98 (t, 1H, J=7.8 Hz), 7.70 (d, 1H, J=7.9 Hz),7.60-7.55 (m, 1H), 7.16 (t, 1H, J=6.7 Hz), 6.84 (d, 1H, J=4.7 Hz), 6.73(d, 1H, J=4.6 Hz), 4.57 (s, 2H), 4.24 (dt, 2H, J=6.6 and 15.2 Hz); MS(Electrospray): M+H=311.0.

EXAMPLE 20

[0341]{3-[2,2-Difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (20)

[0342] Prepared following a similar protocol as described in example 19,{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester (preparation described in example 18, step C) wasconverted to{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid.

EXAMPLE 21

[0343]{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid

[0344] Step A

[0345] [3-(Cyclopropylmethyl-amino)-propyl]-carbamic Acid Benzyl Ester(21-1)

[0346] A solution of cyclopropanecarbaldehyde (4.6 ml, 0.061 mol),(3-amino-propyl)-carbamic acid benzyl ester hydrochloride (15 g, 0.061mol) and triethylamine (8.5 ml, 0.061 mol) in methanol (244 ml) wasstirred at room temperature overnight. Sodium borohydride (3.7 g, 0.098mol) was added and the reaction mixture was stirred at room temperaturefor 4 h. Sodium hydroxide solution (1N) was added and the reaction wasconcentrated to remove methanol. The residue was extracted with ethylacetate and the combined extracts were washed with brine. Drying andsolvent evaporation gave an oil; flash chromatography (silica gel,chloroform saturated with ammonia-2-propanol, 99.5:0.5) gave[3-(cyclopropylmethyl-amino)-propyl]-carbamic acid benzyl ester; ¹H NMR(CDCl₃, 400 MHz) δ 7.35 (m, 5H), 5.60 (bs, 1H), 5.10 (s, 2H), 3.30 (q,2H, J=6.1 Hz), 2.70 (t, 2H, J=6.5 Hz), 2.43 (d, 2H, J=6.8 Hz), 1.67 (m,2H), 0.92 (m, 1H), 0.46 (m, 2H), 0.099 (q, 2H, J=4.9 Hz).

[0347] Step B

[0348] (3-Benzyloxycarbonylamino-propyl)-cyclopropylmethyl-carbamic AcidTert-Butyl Ester (21-2)

[0349] A solution of [3-(cyclopropylmethyl-amino)-propyl]-carbamic acidbenzyl ester (3.6 g, 0.014 mol) and di-tert-butyl dicarbonate (3 g,0.014 mol) in methylene chloride (75 ml) was stirred at room temperaturefor 1 h. Concentration and flash chromatography (silica gel,hexane-ethyl acetate, 85:15-83:17) gave(3-benzyloxycarbonylamino-propyl)-cyclopropylmethyl-carbamic acidtert-butyl ester; ¹H NMR (CDCl₃, 400 MHz) δ 7.36 (m, 5H), 5.09 (s, 2H),3.36 (m, 2H), 3.18 (m, 2H), 3.04 (m, 2H), 1.64 (m, 2H), 1.45 (s, 9H),0.95 (m, 1H), 0.48 (m, 2H), 0.19 (q, 2H, J=4.9 Hz).

[0350] Step C

[0351] (3-Amino-propyl)-cyclopropylmethyl-carbamic Acid Tert-Butyl Ester(21-3)

[0352] A solution of(3-benzyloxycarbonylamino-propyl)-cyclopropylmethyl-carbamic acidtert-butyl ester (4.2 g, 0.012 mol) in ethanol (60 ml) was stirred inthe presence of palladium on carbon (10%, 0.42 g) under a hydrogenatmosphere for 2 h. Filtration through celite and concentration gave(3-amino-propyl)-cyclopropylmethyl-carbamic acid tert-butyl ester; ¹HNMR (CDCl₃, 400 MHz) δ 3.35 (m, 2H), 3.08 (m, 2H), 2.70 (t, 2H, J=6.8Hz), 1.67 (m, 2H), 1.46 (s, 9H), 1.30 (bs, 2H), 0.97 (m, 1H), 0.48 (m,2H), 0.20 (q, 2H, J=5 Hz).

[0353] Step D

[0354]{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticAcid Ethyl Ester (214)

[0355] A solution of (3-amino-propyl)-cyclopropylmethyl-carbamic acidtert-butyl ester (5 g, 0.022 mol),(3-bromo-2-oxo-2H-pyrazin-1-yl)-acetic acid ethyl ester (5.2 g, 0.020mol, preparation described in example 17, step J) and triethylamine (3.3ml, 0.024 mol) in ethanol (16 ml) was heated to 80° C. in a sealed tubeovernight. Concentration and flash chromatography (silica gel,chloroform-diethyl ether, 90: 10) gave{3-[3(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester; ¹H NMR (CDCl₃, 400 MHz) δ 6.85 (d, 1H, J=4.7 Hz), 6.36(d, 1H, J=4.7 Hz), 4.56 (s, 2H), 4.25 (q, 2H, J=7.1 Hz), 3.42 (m, 2H),3.36 (m, 2H), 3.10 (m, 2H), 1.87 (m, 2H), 1.46 (s, 9H), 1.30 (t, 3H,J=7.1 Hz), 0.96 (m, 1H), 0.48 (m, 2H), 0.20 (m, 2H).

[0356] Step E

[0357]{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (21-5)

[0358] A solution of{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester (250 mg, 0.61 mmol) and lithium hydroxide monohydrate(33 mg, 0.79 mmol) in water (0.72 ml) and methanol (3.6 ml) was stirredat room temperature for 2 h. Hydrochloric acid solution (1N, 0.79 ml)was added and the reaction mixture was stirred at room temperature for10 min. Concentration from methanol gave{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid; ¹H NMR (CD₃OD, 400 MHz) δ 6.78 (d, 1H, J=4.8 Hz), 6.69 (d, 1H,J=4.9 Hz), 4.61 (s, 2H), 3.32 (m, 4H), 3.12 (d, 2H, J=6.8 Hz), 1.89 (m,2H), 1.45 (s, 9H), 1.00 (m, 1H), 0.48 (m, 2H), 0.22 (m, 2H).

EXAMPLE 22

[0359]{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticAcid

[0360] Step A

[0361]{3-3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticAcid Ethyl Ester (22-1)

[0362] A solution of{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester (250 mg, 0.61 mmol, preparation described in example21, step D) and N-chlorosuccinimide (73 mg, 0.55 mmol) in1,2-dichloroethane (4.2 ml) was heated to 80° C. for 1.5 h. AdditionalN-chlorosuccinimide (8 mg) was added and the reaction mixture was heatedfor 1 h. Concentration and flash chromatography (silica gel,hexane-ethyl acetate, 80:20) gave{3-[3-(tert-butoxycarbonylcyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester (0.22 g, 81%); ¹H NMR (CDCl₃, 400 MHz) δ 6.94 (s, 1H),4.90 (s, 2H), 4.26 (q, 2H, J=7.1 Hz), 3.40 (m, 4H), 3.10 (m, 2H), 1.87(m, 2H), 1.48 (s, 9H), 1.31 (t, 3H, J=7.1 Hz), 0.97 (m, 1H), 0.49 (m,2H), 0.21 (m, 2H).

[0363] Step B

[0364]{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid (22-2)

[0365] A solution of{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid ethyl ester (0.22 g, 0.50 mmol) and lithium hydroxide monohydrate(27 mg, 0.65 mmol) in water (0.65 ml) and methanol (3 ml) was stirred atroom temperature for 1.5 h. Hydrochloric acid solution (IN, 0.65 ml) wasadded and the reaction mixture was stirred at room temperature for 5min. Concentration from methanol gave{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid; ¹H NMR (CD₃OD, 400 MHz) δ 6.90 (s, 1H), 4.90 (s, 2H), 3.34 (m,4H), 3.11 (d, 2H, J=6.8 Hz), 1.88 (m, 2H), 1.45 (s, 9H), 0.99 (m, 1H),0.49 (m, 2H), 0.22 (m, 2H).

EXAMPLE 23

[0366][6-Chloro-(S)-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid

[0367] Step A

[0368](S)-[3-(1-Azidomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid Ethyl Ester (23-1)

[0369] To a solution of (3-bromo-2-oxo-2H-pyrazin-1-yl)-acetic acidethyl ester (8.75 g, 33.5 mmol, preparation described in example 17,step J) in EtOH (60 ml) was added (S)-1-azidomethyl-2-phenyl-ethylaminehydrochloride (7.5 g, 35.3 mmol, prepared from(S)-(−)-2-(tertbutoxycarbonylamino)-3-phenyl-1-propanol following theprocedure of Horwell et al (J. Med. Chem. 1991, 34, 404-414) and Bocremoval under standard HCl(g) conditions) and triethylamine (10.8 ml,77.6 mmol). The pressure flask was flushed with argon, sealed and thereaction mixture was stirred at 110° C. for 3 days. The reaction mixturewas concentrated in vacuo and purified by flash chromatography (silicagel, 20% EtOAc in hexane to 40%) to give(S)-[3-(1-azidomethyl-2-phenylethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester as a brown syrup. ¹H NMR (CDCl₃, 400 MHz): δ 7.36-7.20(m, 5H); 6.85 (d, J=4.4 Hz, 1H); 6.41 (d, J=4.4 Hz, 1H); 6.20 (bd, J=8Hz, 1H); 4.58 (A of AB, d, J=17.5 Hz, 1H));); 4.52 (B of AB, d, J=17.5Hz, 1H)); 4.43-4.33 (m, 1H); 4.25 (q, J=7.3 Hz, 2H); 3.52 (A of ABX, dd,J=12.5, 5 Hz, 1H); 3.40 (B of ABX, dd, J=12.5, 5 Hz, 1H); 3.00 (A ofABX, dd, J=14, 6.7 Hz, 1H); 2.92 (B of ABX, dd, J=14, 7.9 Hz, 1H); 1.29(t, J=7.3 Hz, 3H).

[0370] Step B

[0371](S)-[3-(1-Azidomethyl-2-phenyl-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticAcid Ethyl Ester (23-2)

[0372] To a solution of(S)-[3-(1-azidomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester (5.8 g, 16.3 mmol) in dichloroethane (90 ml) was addedN-chlorosuccinimide (2.17 g, 16.3 mmol) and the reaction mixture wasstirred at 85° C. for 1 h 30 and at room temperature for 18 h. Thereaction mixture was concentrated in vacuo and purified by flashchromatography (silica gel, 20% diethyl ether in hexane to 45%) to give(S)-[3-(1-azidomethyl-2-phenyl-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester as a thick syrup. ¹H NMR (CDCl₃, 400 MHz): δ 7.38-7.20(m, 5H); 6.85 (s, 1H); 6.10 (bd, J=8.8 Hz,1H); 4.92 (A of AB, d, J=17.7Hz, 1H));); 4.86 (B of AB, d, J=17.7 Hz, 1H)); 4.40-4.30 (m, 1H); 4.25(q, J=7 Hz, 2H); 3.52 (A of ABX, dd, J=12.4, 4.6 Hz, 1H); 3.40 (B ofABX, dd, J=12.4, 4.6 Hz, 1H); 3.00 (A of ABX, dd, J=13.5, 6.4 Hz, 1H);2.92 (B of ABX, dd, J=13.5, 7.4 Hz, 1H); 1.29 (t, J=7 Hz, 3H).

[0373] Step C

[0374](S)-[3-(1-Aminomethyl-2-phenyl-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticAcid Ethyl Ester (23-3)

[0375] To a solution of(S)-[3-(1-azidomethyl-2-phenyl-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester (5.67 g, 14.5 mmol) in MeOH (80 ml) and THF (40 ml) wasadded SnCl₂ (4.1 g, 21.8 mmol) and the reaction mixture was stirred atroom temperature for 18 h. The reaction mixture was concentrated invacuo, azeotroped with CH₂Cl₂, and purified by flash chromatography(silica gel, 6% MeOH containing 10% NH₄OH in CH₂Cl₂ to 10%) to give(S)-[3-(1-aminomethyl-2-pheny-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester as a beige solid.

[0376]¹H NMR (CDCl₃, 400 MHz): δ 7.35-7.15 (m, 5H); 6.92 (s, 1H); 6.17(bd, J=8.5 Hz, 1H); 4.88 (s, 2H));); 4.35-4.15(m, 3H); 3.00-2.70 (m,4H); 1.32 (t, J=6.9 Hz, 3 H); rotation: [α]_(d)=−82.6° (c=0.42, MeOH).

[0377] Step D

[0378][6-Chloro-(S)-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid Ethyl Ester (23-4)

[0379] To a solution of(S)-[3-(1-aminomethyl-2-phenyl-ethylamino)-6-chloro-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester (700 mg, 1.92 mmol) in DCE (20 ml) was addedformaldehyde (719 ul of a 37% solution in water, 9.59 mmol) and sodiumtriacetoxyborohydride (813 mg, 3.84 mmol) and the reaction mixture wasstirred at room temperature for 1.5 h. The reaction mixture was dilutedwith CH₂Cl₂ and quenched with 1N NaOH and water, and stirred at roomtemperature for 5 min. The organic layer was separated and the aqueouslayer extracted with CH₂Cl₂ twice. The combined organic layer was washedwith brine, dried on Na₂SO₄, and purified by flash chromatography(silica gel, 2% MeOH containing 10% NH₄OH in CH₂Cl₂ to 4%) to give[6-chloro-(S)-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester as an oil. ¹H NMR (CDCl₃, 400 MHz): δ 7.35-7.15 (m,5H); 6.93 (s, 1H); 6.15 (bd, J=6.9 Hz, 1H); 4.92 (A of AB, d, J=17 Hz,1H); 4.86 (B of AB, d, J=17 Hz, 1H); 4.32-4.22 (m, 1H); 4.27 (q, J=7.5Hz, 2H); 3.05 (A of ABX, dd, J=13.6, 4.8 Hz, 1H); 2.87 (B of ABX, dd,J=13.6, 6.1 Hz, 1H); 2.37 (A of ABX, dd, J=12.2, 8.3 Hz, 1H); 2.27 (B ofABX, dd, J=12.2, 6.1 Hz, 1H); 1.29 (t, J=7.5 Hz, 3H).

[0380] Step E

[0381][6-Chloro-(S)-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticAcid (23-5)

[0382] To a solution of[6-chloro-(S)-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2oxo-2H-pyrazin-1-yl]-aceticacid ethyl ester (385 mg, 0.98 mmol) in THP (6 ml) is added 1N LiOH(1.27 ml, 1.27 mmol) and the reaction mixture is stirred at roomtemperature for 3 h. To the reaction mixture is added 1N HCl (1.27 ml,1.27 mmol) and the reaction mixture is concentrated in vacuo, azeotropedwith methanol and dried on high vacuum to give[6-chloro-(S)-3-(1-dimethylaminomethyl-2-phenylethylamino)-2-oxo-2H-pyrazin-1-yl)-aceticacid as a white solid which contains 1.3 eq LiCl. ¹H NMR (CD₃OD, 400MHz): δ 7.30-7.15 (m, 5H); 6.86 (s, 1H); 4.80 (A of AB, d, J=16.7 Hz,1H); 4.76-4.66 (m, 1H); 4.56 (B of AB, d, J=16.7 Hz, 1H); 3.45 (A ofABX, dd, J=13, 12.9 Hz, 1H); 3.25 (B of ABX, dd, J=13, 3.4 Hz, 1H);3.00-2.85 (m, 2H).

EXAMPLE 24

[0383]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,3]thiadiazol-4-yl-benzyl)-acetamide

[0384] Step A

[0385]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,3]thiadiazol-4-yl-benzyl)-acetamide(24-1)

[0386] A solution of[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (70 mg, 0.16 mmol, preparation described in example 17),2-[1,2,3]thiadiazole4-yl-benzylamine (40 mg, 0.21 mmol, preparationdescribed in example 1), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (46 mg, 0.24 mmol), 1-hydroxy-7-azabenzotriazole (33 mg,0.24 mmol) and diisopropylethylamine (42 ul, 0.24 mmol) inN,N-dimethylformamide (2 ml) was stirred at room temperature overnight.Water was added and the reaction mixture was extracted with ethylacetate. The combined organic layers were washed with brine. Drying andsolvent evaporation gave an oil; flash chromatography (silica gel,chloroform-2-propanol-ammonium hydroxide, 99:1:0.1-98:2:0.2) gave2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,3]thiadiazol-4-yl-benzyl)-acetamide;¹H NMR (CDCl₃, 400 MHz) δ 8.66 (m, 2H), 7.82 (dt, 1H, J=7.8 Hz, J=1.6Hz), 7.69 (m, 1H), 7.64 (m, 1H), 7.53 (m, 1H), 7.48-7.38 (m, 3H), 6.92(s, 1H), 6.47 (t, 1H, J=6 Hz), 4.81 (s, 2H), 4.47 (d, 2H, J=6.3 Hz),4.36 (dt, 2H, J=14 Hz, J=6.4 Hz); MS (ES+) M+1 518.45 forC₂₂H₁₈ClF₂N₇O₂.

EXAMPLE 25

[0387]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,3]thiadiazol-4-yl-benzyl)-acetamide

[0388] Step A

[0389]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[(1,2,3]thiadiazol-4-yl-benzyl)-acetamide(25-1)

[0390] A solution of{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (75 mg, 0.16 mmol, preparation described in example 18),2-[1,2,3]thiadiazole-4-yl-benzylamine (40 mg, 0.21 mmol, preparationdescribed in example 1), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydrochloride (46 mg, 0.24 mmol), 1-hydroxy-7-azabenzotriazole (33 mg,0.24 mmol) and diisopropylethylamine (42 ul, 0.24 mmol) inN,N-dimethylformamide (2 ml) was stirred at room temperature overnight.Water was added and the reaction mixture was extracted with ethylacetate. The combined organic layers were washed with brine. Drying andsolvent evaporation gave an oil; flash chromatography (silica gel,chloroform saturated with ammonia-2-propanol 98:2) gave2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,3]thiadiazol-4-yl-benzyl)-acetamide;¹H NMR (CDCl₃,400 MHz) δ 8.66 (s, 1H), 8.25 (d, 1H, J=6.4 Hz), 7.62 (m,2H), 7.54 (m, 1H), 7.44 (m, 2H), 7.32 (m, 2H), 6.83 (s, 1H), 6.35 (t,1H, J=8 Hz), 4.79 (s, 2H), 4.63 (m, 2H), 4.45 (d, 2H, J=6.3 Hz); MS(ES+) M+1 534.4 for C₂₂H₁₈ClF₂N₇O₃S.

EXAMPLE 26

[0391]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-tetrazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0392] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-tetrazol-1-yl-benzylamine (preparation described in example 3) wereconverted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-tetrazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 502.4 for C₂₁H₁₈ClF₂N₉O₂.

EXAMPLE 27

[0393]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamide

[0394] Prepared following a similar protocol as described in example 24,{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 18) and2-tetrazol-1-yl-benzylamine (preparation described in example 3) wereconverted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 518.5 for C₂₁H₁₈ClF₂N₉O₃.

EXAMPLE 28

[0395]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-pyrazol-1-yl-benzyl)-acetamide

[0396] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-pyrazol-1-yl-benzylamine trifluoroacetic acid salt (preparationdescribed in example 5) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-pyrazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 500.4 for C₂₃H₂₀ClF₂N₇O₂.

EXAMPLE 29

[0397]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-imidazol-2-yl)-benzyl]-acetamide

[0398] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1H-imidazol-2-yl)-benzylamine (preparation described in example 6)were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-imidazol-2-yl)-benzyl]-acetamide;MS (ES+) M+1 500.5 for C₂₃H₂₀ClF₂N₇O₂.

EXAMPLE 30

[0399]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide

[0400] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1,2,4-triazol-1-yl)benzylamine (preparation described in example 9)were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 501.5 for C₂₂H₁₉CF₂N₈O₂.

EXAMPLE 31

[0401]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0402] Prepared following a similar protocol as described in example 24,(6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 18) and2-(1,2,4-triazol-1-yl)benzylamine (preparation described in example 9)were converted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 517.5 for C₂₂H₁₉ClF₂N₈O₃.

EXAMPLE 32

[0403]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-imidazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0404] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-imidazol-1-yl-benzylamine (preparation described in example 13) wereconverted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-imidazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 500.51 for C₂₃H₂₀ClF₂N₇O₂.

EXAMPLE 33

[0405]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-4-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0406] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1,2,4-triazol-4-yl)benzylamine (preparation described in example 10)were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-4-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 501.5 for C₂₂H₁₉ClF₂N₈O₂.

EXAMPLE 34

[0407]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-acetamideTrifluoroacetic Acid Salt

[0408] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) andC-(3-[1,2,4]triazol-1-yl-pyridin-2-yl)-methylamine 15 hydrochloride salt(preparation described in example 7) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-y-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 502.5 for C₂₁H₁₈ClF₂N₉O₂.

EXAMPLE 35

[0409]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-acetamide

[0410] Prepared following a similar protocol as described in example 24,{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl}-ethylamino]-2-oxo-2H-pyrazin-1-yl)-aceticacid (preparation described in example 18) andC-(3-[1,2,4]triazol-1-yl-pyridin-2-yl)-methylamine hydrochloride salt(preparation described in example 7) were converted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(3-[1,2,4]triazol-1-yl-pyridin-2-ylmethyl)-acetamide;MS (ES+) M+1 518.4 for C₂₁H₁₈ClF₂N₉O₃.

EXAMPLE 36

[0411]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamide

[0412] Prepared following a similar protocol as described in example 24,(6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 536.4 for C₂₁H₁₇Cl₂F₂N₉O₂.

EXAMPLE 37

[0413] 2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamide

[0414] Prepared following a similar protocol as described in example 24,{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 18) and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 552.3 for C₂₁H₁₇Cl₂F₂N₉O₃.

EXAMPLE 38

[0415]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-imidazol-4-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0416] Step A

[0417]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1-trityl-1H-imidazol-4-yl)-benzyl]-acetamide

[0418] A solution of[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (25 mg, 0.058 mmol, preparation described in example 17),2-(1-trityl-1H-imidazol-4-yl)-benzylamine oxalate salt (35 mg, 0.070mmol, preparation described in example 2),1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (17 mg,0.087 mmol), 1-hydroxy-7-azabenzotriazole (12 mg, 0.087 mmol) anddiisopropylethylamine (40 ul, 0.23 mmol) in N,N-dimethylformamide (1 ml)was stirred at room temperature overnight. Water was added and thereaction mixture was extracted with ethyl acetate. The combined organiclayers were washed with brine. Drying and solvent evaporation gave2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1-trityl-1H-imidazol-4-yl)-benzyl]-acetamide;¹H NMR (CDCl₃, 300 MHz) δ 9.11 (m, 1H), 8.65 (d, 1H, J=4.6 Hz), 8.02 (s,1H), 7.80 (m, 1H), 7.61 (m, 1H), 7.47 (m, 1H), 7.38-7.15 (m, 18H), 6.99(d, 1H, J=1.2 Hz), 6.78 (s, 1H), 6.36 (m, 1H), 4.78 (s, 2H), 4.43 (d,2H, J=6.4 Hz), 4.14 (m, 2H).

[0419] Step B

[0420]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-imidazol-4-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0421] To a solution of2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1-trityl-1H-imidazol-4-yl)-benzyl]-acetamide(47 mg, 0.058 mmol) in trifluoroacetic acid (1.5 ml) was addedtriethylsilane (excess) until completion of the reaction. Concentrationand purification by reverse phase preparative HPLC (5% to 95% CH₃CN inwater containing 0.1% TFA, C18 PRO YMC 20×150 mm) gave2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-imidazol-4-yl)-benzyl]-acetamideTFA salt; ¹H NMR (CD₃OD, 400 MHz) δ 8.95 (d, 1H, J=1.3 Hz), 8.63 (d, 1H,J=4.1 Hz), 7.94 (dt, 1H, J=7.7 Hz, J=1.6 Hz), 7.70 (m, 2H), 7.51 (m,6H), 6.83 (s, 1H), 4.80 (s, 2H), 4.46 (s, 2H), 4.28 (t, 2H, J=14.1 Hz);MS (ES+) M+1 500.4 for C₂₃H₂₀ClF₂N₇O₂.

EXAMPLE 39

[0422]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-tetrazol-5-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0423] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1H-tetrazol-5-yl)-benzylamine hydrochloride salt (preparationdescribed in example 14) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-tetrazol-5-yl)-benzyl]-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 502.4 for C₂₁H₁₈ClF₂N₉O₂.

EXAMPLE 40

[0424]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0425] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt;

[0426] MS (ES+) M+1 535.4 for C₂₂H₁₈Cl₂F₂N₈O₂.

EXAMPLE 41

[0427]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0428] Prepared following a similar protocol as described in example 24,{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 18) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 551.4 for C₂₂H₁₈Cl₂F₂N₈O₃.

EXAMPLE 42

[0429]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(3-tetrazol-1-yl-pyridin-2-ylmethyl)-acetamide

[0430] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and3-(tetrazol-1-yl)-2-aminomethylpyridine (preparation described inexample 11) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(3-tetrazol-1-yl-pyridin-2-ylmethyl)-acetamide;MS (ES+) M+1 503.4 for C₂₀H₁₇ClF₂N₁₀O₂.

EXAMPLE 43

[0431]2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(3-tetrazol-1-yl-pyridin-2-ylmethyl)-acetamideTrifluoroacetic Acid Salt

[0432] Prepared following a similar protocol as described in example 24,{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl}-ethylamino]-2-oxo-2H-pyrazin-1-yl)-aceticacid (preparation described in example 18) and3-(tetrazol-1-yl)-2-aminomethylpyridine (preparation described inexample 11) were converted to2-{6-chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(3-tetrazol-1-yl-pyridin-2-ylmethyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 519.0 for C₂₀H₁₇ClF₂N₁₀O₃.

EXAMPLE 44

[0433]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-pyrazol-3-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0434] Prepared following a similar protocol as described in example 24,(6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1H-pyrazol-3-yl)-benzylamine hydrochloride salt (preparationdescribed in example 12) were converted to2-[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1H-pyrazol-3-yl)-benzyl]-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 500.1 for C₂₃H₂₀ClF₂N₇O₂.

EXAMPLE 45

[0435]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1-methyl-1H-tetrazol-5-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0436] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(1-methyl-1H-tetrazol-5-yl)-benzylamine hydrochloride salt(preparation described in example 15) were converted to2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(1-methyl-1H-tetrazol-5-yl)-benzyl]-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 516.4 for C₂₂H₂₀ClF₂N₉O₂.

EXAMPLE 46

[0437]2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(2-methyl-2H-tetrazol-5-yl)-benzyl]-acetamideTrifluoroacetic Acid Salt

[0438] Prepared following a similar protocol as described in example 24,[6-chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 17) and2-(2-methyl-2H-tetrazol-5-yl)-benzylamine hydrochloride salt(preparation described in example 16) were converted to2-[6-Chloro-3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-[2-(2-methyl-2H-tetrazol-5-yl)-benzyl]-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 516.4 for C₂₂H₂₀ClF₂N₉O₂.

EXAMPLE 47

[0439]N-(5-Chloro-2-tetrazol-1-yl-benzyl)-2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-acetamide

[0440] Prepared following a similar protocol as described in example 24,[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticacid (preparation described in example 19) and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted toN-(5-chloro-2-tetrazol-1-yl-benzyl)-2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-acetamide;MS (ES+) M+1 502.4 for C₂₁H₁₈ClF₂N₉O₂.

EXAMPLE 48

[0441]2-[3-(2,2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide

[0442] Prepared following a similar protocol as described in example 24,[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticacid (preparation described in example 19) and2-(1,2,4-triazol-1-yl)benzylamine (preparation described in example 9)were converted to2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 467.1 for C₂₂H₂₀F₂N₈O₂.

EXAMPLE 49

[0443]N-(5-Chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-acetamide

[0444] Prepared following a similar protocol as described in example 24,[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticacid (preparation described in example 19) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted toN-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-acetamide;MS (ES+) M+1 501.0 for C₂₂H₁₉ClF₂N₈O₂.

EXAMPLE 50

[0445]2-[3-(2,2-Difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-tetrazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0446] Prepared following a similar protocol as described in example 24,[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]aceticacid (preparation described in example 19) and2-tetrazol-1-yl-benzylamine (preparation described in example 3) wereconverted to2-[3-(2,2-difluoro-2-pyridin-2-yl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(2-tetrazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt; MS (ES+) M+1 468.1 for C₂₁H₁₉F₂N₉O₂.

EXAMPLE 51

[0447]2-{3-[2,2-Difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamideTrifluoroacetic Acid Salt

[0448] Prepared following a similar protocol as described in example 24,{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 20) and2-tetrazol-1-yl-benzylamine (preparation described in example 3) wereconverted to2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamidetrifluoroacetic acid salt;

[0449] MS (ES+) M+1 484.1 for C₂₁H₁₉F₂N₉O₃.

EXAMPLE 52

[0450]2-{3-[2,2-Difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl)—N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide

[0451] Prepared following a similar protocol as described in example 24,(3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 20) and2-(1,2,4-triazol-1-yl)benzylamine (preparation described in example 9)were converted to2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 483.1 for C₂₂H₂₀F₂N₈O₃.

EXAMPLE 53

[0452]N-(5-Chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-acetamide

[0453] Prepared following a similar protocol as described in example 24,{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 20) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted toN-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}acetamide; MS (ES+) M+1 517.5 for C₂₂H₁₉ClF₂N₈O₃.

EXAMPLE 54

[0454]N-(5-Chloro-2-tetrazol-1-yl-benzyl)-2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-acetamide

[0455] Prepared following a similar protocol as described in example 24,{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 20) and and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted toN-(5-chloro-2-tetrazol-1-yl-benzyl)-2-{3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-acetamide;MS (ES+) M+1 518.4 for C₂₁H₁₈ClF₂N₉O₃.

EXAMPLE 55

[0456]N-(5-Chloro-2-tetrazol-1-yl-benzyl)-2-{3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-acetamideHydrochloride Salt

[0457] Step A

[0458](3-{4-[(5-Chloro-2-tetrazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-yl}amino]-propyl)-cyclopropylmethyl-carbamicAcid Tert-Butyl Ester

[0459] Prepared following a similar protocol as described in example 24,{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 21) and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted to3-{4-[(5-chloro-2-tetrazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester; MS (ES+) M+1 572.5 for C₂₆H₃₄ClN₉O₄.

[0460] Step B

[0461]N-(5-Chloro-2-tetrazol-1-yl-benzyl)-2-{3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-acetamideHydrochloride Salt

[0462] Through a solution of3-{4-[(5-chloro-2-tetrazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester (74 mg, 0.13 mmol) in ethyl acetate (20 ml),cooled to 0° C. was bubbled HCl (g) for 8 min. The reaction was stirredat room temperature for 0.5 h. Nitrogen was bubbled through the reactionmixture. Concentration from ethyl acetate and trituration from ethylacetate-ether gaveN-(5-chloro-2-tetrazol-1-yl-benzyl)-2-{3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-acetamidehydrochloride salt; MS (ES+) M+1 472.5 for C₂₁H₂₆ClN₉O₂.

EXAMPLE 56

[0463]N-(5-Chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-{3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-acetamideHydrochloride Salt

[0464] Step A

[0465](3-4-[(5-Chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-propyl)-cyclopropylmethyl-carbamicAcid Tert-Butyl Ester

[0466] Prepared following a similar protocol as described in example 24,{3-[3-(tert-butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 21) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted to(3-{4-[(5-chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester; MS (ES+) M+1 571.5 for C₂₇H₃₅ClN₈O₄.

[0467] Step B

[0468]N-(5-Chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-[3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl]-acctamideHydrochloride Salt

[0469] Prepared following a similar protocol as described in example 55,step B,(3-(4-[(5-chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester was converted toN-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-{3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-acetamidehydrochloride salt; MS (ES+) M+1 471.5 for C₂₂H₂₇ClN₈O₂.

EXAMPLE 57

[0470]2-{6-Chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamideHydrochloride Salt

[0471] Step A

[0472](3-{5-Chloro-3-oxo-4-[(2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicAcid Tert-Butyl Ester

[0473] Prepared following a similar protocol as described in example 24,{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 22) and2-(1,2,4-triazol-1-yl)benzylamine (preparation described in example 9)were converted to(3-{5-chloro-3-oxo-4-[(2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester; MS (ES+) M+1 571.5 for C₂₇H₃₅ClN₈O₄.

[0474] Step B

[0475]2-{6-Chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamideHydrochloride Salt

[0476] Prepared following a similar protocol as described in example 55,step B,(3-{5-chloro-3-oxo-4-[(2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester was converted to2-{6-chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1yl}-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide hydrochloride salt; MS(ES+) M+1 471.8 for C₂₂H₂₇ClN₈O₂.

EXAMPLE 58

[0477]2-{6-Chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamideHydrochloride Salt

[0478] Step A

[0479](3-{5-Chloro-4-[(5-chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicAcid Tert-Butyl Ester

[0480] Prepared following a similar protocol as described in example 24,{3-[3-(tert-Butoxycarbonyl-cyclopropylmethyl-amino)-propylamino]-6-chloro-2-oxo-2H-pyrazin-1-yl}-aceticacid (preparation described in example 22) and5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparation described inexample 8) were converted to(3-{5-chloro-4-[(5-chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester; MS (ES+) M+1 605.5 for C₂₇H₃₄Cl₂N₈O₄.

[0481] Step B

[0482]2-{6-Chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamideHydrochloride Salt

[0483] Prepared following a similar protocol as described in example 55,step B,(3-{5-chloro-4-[(5-chloro-2-[1,2,4]triazol-1-yl-benzylcarbamoyl)-methyl]-3-oxo-3,4-dihydro-pyrazin-2-yl-amino}-propyl)-cyclopropylmethyl-carbamicacid tert-butyl ester was converted to2-{6-chloro-3-[3-(cyclopropylmethyl-amino)-propylamino]-2-oxo-2H-pyrazin-1-yl}-N-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-acetamidehydrochloride salt; MS (ES+) M+1 505.8 for C₂₂H₂₆Cl₂N₈O₂.

EXAMPLE 59

[0484]2-(6-Methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-N-(2-tetrazol-1-yl-benzyl)-acetamide

[0485] Prepared following a similar protocol as described in example 24,(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-aceticacid (preparation described in Sanderson et.al., J. Med. Chem. 1998, 41,4466-4474) and 2-tetrazol-1-yl-benzylamine (preparation described inexample 3) were converted to2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-N-(2-tetrazol-1-yl-benzyl)acetamide;MS (ES+) M+1 494.5 for C₂₃H₂₃N₇O₄S.

EXAMPLE 60

[0486]N-(5-Chloro-2-tetrazol-1-yl-benzyl)-2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-acetamide

[0487] Prepared following a similar protocol as described in example 24,(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-aceticacid (preparation described in Sanderson et.al., J. Med. Chem. 1998, 41,4466-4474) and 5-chloro-2-tetrazol-1-yl-benzylamine (preparationdescribed in example 4) were converted toN-(5-chloro-2-tetrazol-1-yl-benzyl)-2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-acetamide;

[0488] MS (ES+) M+1 528.4 for C₂₃H₂₂ClN₇O₄S.

EXAMPLE 61

[0489]N-(5-Chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-acetamide

[0490] Prepared following a similar protocol as described in example 24,(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-aceticacid (preparation described in Sanderson et.al., J. Med. Chem. 1998, 41,4466-4474) and 5-chloro-2-[1,2,4]triazol-1-yl-benzylamine (preparationdescribed in example 8) were converted toN-(5-chloro-2-[1,2,4]triazol-1-yl-benzyl)-2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-acetamide;MS (ES+) M+1 527.4 for C₂₄H₂₃ClN₆O₄S.

EXAMPLE 62

[0491]2-(6-Methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide

[0492] Prepared following a similar protocol as described in example 24,(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-aceticacid (preparation described in Sanderson et.al., J. Med. Chem. 1998, 41,4466-4474) and 2-(1,2,4-triazol-1-yl)benzylamine (preparation describedin example 9) were converted to2-(6-methyl-2-oxo-3-phenylmethanesulfonylamino-2H-pyridin-1-yl)-N-(2-[1,2,4]triazol-1-yl-benzyl)-acetamide;MS (ES+) M+1 493.5 for C₂₄H₂₄N₆O₄S.

EXAMPLE 63

[0493]2-[6-Chloro-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamideHydrochloride Salt

[0494] Prepared following a similar protocol as described in example 24,[6-chloro-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-aceticacid (preparation described in example 23) and5-chloro-2-tetrazol-1-yl-benzylamine (preparation described in example4) were converted to2-[6-chloro-3-(1-dimethylaminomethyl-2-phenyl-ethylamino)-2-oxo-2H-pyrazin-1-yl]-N-(5-chloro-2-tetrazol-1-yl-benzyl)-acetamidehydrochloride salt; MS (ES+) M+1 556.0 for C₂₅H₂₇Cl₂N₉O₂.

[0495] Typical tablet cores suitable for administration of thrombininhibitors are comprised of, but not limited to, the following amountsof standard ingredients: General Range Preferred Range Most PreferredExcipient (%) (%) Range (%) mannitol 10-90 25-75 30-60 microcrystalline10-90 25-75 30-60 cellulose magnesium stearate 0.1-5.0 0.1-2.5 0.5-1.5

[0496] In Vitro Assay for Determining Proteinase Inhibition

[0497] Assays of human α-thrombin and human trypsin were performed bythe methods substantially as described in Thrombosis Research, Issue No.70, page 173 (1993) by S. D. Lewis et al. In certain studies with potentinhibitors (K_(i)<10 nM) where the degree of inhibition of thrombin washigh, a more sensitive activity assay was employed. In this assay therate of thrombin catalyzed hydrolysis of the fluorogenic substrateZ-GPR-afc (K_(m)=27 μM) was determined from the increase in fluorescenceat 500 nm (excitation at 400 nm) associated with production of7-amino-4-trifluoromethyl coumarin. Concentrations of stock solutions ofZ-GPR-afc were determined from measurements of absorbance at 380 nm ofthe 7-amino-4trifluoromethyl coumarin produced upon complete hydrolysisof an aliquot of the stock solution by thrombin. Activity assays wereperformed by diluting a stock solution of substrate at least tenfold toa final concentration <0.1 Km into a solution containing enzyme orenzyme equilibrated with inhibitor. Times required to achieveequilibration between enzyme and inhibitor were determined in controlexperiments. The activities shown by this assay indicate that thecompounds of the invention are therapeutically useful for treatingvarious conditions in patients suffering from unstable angina,refractory angina, myocardial infarction, transient ischemic attacks,atrial fibrillation, thrombotic stroke, embolic stroke, deep veinthrombosis, disseminated intravascular coagulation, and reocclusion orrestenosis of recanalized vessels.

EXAMPLE 64

[0498] Tablet Preparation

[0499] Tablets containing 25.0, 50.0, and 100.0 mg., respectively, ofthe following active compounds are prepared as illustrated below(compositions A-C). Active I is compound2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamide.Amount-(mg) Component A B C Active I 25 50 100 Microcrystallinecellulose 37.25 100 200 Modified food corn starch 37.25 4.25 8.5Magnesium stearate 0.5 0.75 1.5

[0500] All of the active compound, cellulose, and a portion of the cornstarch are mixed and granulated to 10% corn starch paste. The resultinggranulation is sieved, dried and blended with the remainder of the cornstarch and the magnesium stearate. The resulting granulation is thencompressed into tablets containing 25.0, 50.0, and 100.0 mg,respectively, of active ingredient per tablet.

EXAMPLE 65

[0501] Tablet Preparation

[0502] Exemplary compositions of compound2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino)-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamide(Active I) tablets are shown below: Component 0.25 mg 2 mg 10 mg 50 mgActive I 0.500% 1.000% 5.000% 14.29% mannitol 49.50% 49.25% 47.25%42.61% microcrystalline cellulose 49.50% 49.25% 47.25% 42.61% magnesiumstearate 0.500% 0.500% 0.500% 0.500%

[0503] Tablet Preparation via Direct Compression

[0504] Active I, mannitol and microcrystalline cellulose were sievedthrough mesh screens of specified size (generally 250 to 750 μm) andcombined in a suitable blender. The mixture was subsequently blended(typically 15 to 30 min) until the drug was uniformly distributed in theresulting dry powder blend. Magnesium stearate was screened and added tothe blender, after which a precompression tablet blend was achieved uponadditional mixing (typically 2 to 10 min). The precompression tabletblend was then compacted under an applied force, typically ranging from0.5 to 2.5 metric tons, sufficient to yield tablets of suitable physicalstrength with acceptable disintegration times (specifications will varywith the size and potency of the compressed tablet). In the case of the2, 10 and 50 mg potencies, the tablets were dedusted and film-coatedwith an aqueous dispersion of water-soluble polymers and pigment.

[0505] Tablet Preparation via Dry Granulation

[0506] Alternatively, a dry powder blend is compacted under modestforces and remilled to afford granules of specified particle size. Thegranules are then mixed with magnesium stearate and tabletted as statedabove.

EXAMPLE 66

[0507] Intravenous Formulations

[0508] Intravenous formulations of compound2-{6-Chloro-3-[2,2-difluoro-2-(1-oxy-pyridin-2-yl)-ethylamino]-2-oxo-2H-pyrazin-1-yl}-N-(2-tetrazol-1-yl-benzyl)-acetamide(Active I) were prepared according to general intravenous formulationprocedures. Component Estimated range Active I 0.12-0.61 mg D-glucuronicacid* 0.5-5 mg Mannitol NF 50-53 mg 1 N Sodium Hydroxide q.s. pH 3.9-4.1Water for injection q.s. 1.0 mL

[0509] Exemplary compositions A-C are as follows: Component A B C ActiveI 0.61 mg* 0.30** 0.15*** D-glucuronic acid* 1.94 mg 1.94 mg 1.94 mgMannitol NF 51.2 mg 51.2 mg 51.2 mg 1 N Sodium Hydroxide q.s. pH 4.0q.s. pH 4.0 q.s. pH 4.0 Water for injection q.s. 1.0 mL q.s. 1.0 mL q.s.1.0 mL

[0510] Various other buffer acids, such as L-lactic acid, acetic acid,citric acid or any pharmaceutically acceptable acid/conjugate base withreasonable buffering capacity in the pH range acceptable for intravenousadministration may be substituted for glucuronic acid.

What is claimed is:
 1. A compound of the general formula:

and pharmaceutically acceptable salts thereof, wherein A is 1) a6-membered non-heterocyclic unsaturated ring system, unsubstituted,monosubstituted, disubstituted, or trisubstituted, same or different,with C₁₋₄ alkyl, 2) a 6-membered heterocyclic unsaturated or saturatedring system wherein 1 ring atom is selected from the group ofheteroatoms consisting of N, O and S, wherein the ring carbons areunsubstituted, monosubstituted, disubstituted, or trisubstituted, sameor different, with C₁₋₄ alkyl,

where R is hydrogen or C₁₋₈alkyl, or 4) —C₃₋₈ cycloalkyl; Z is—(CH₂)₂₋₄—, —CF₂(CH₂)₁₋₃—, —(CH₂)₁₋₃SO₂—, —(CH₂)₁₋₂NH(CH₂)₁₋₄—, or—CH₂CH(R⁴)—, where R⁴ is —(CH₂)₁₋₂N(R⁵R⁶), and R⁵ and R⁶, same ordifferent, are selected from the group consisting of hydrogen andC₁₋₄alkyl; X is CH or N; R¹ is hydrogen, halogen, or C₁₋₄alkyl; R² is

R³ is selected from the group consisting of 1) hydrogen, 2) halogen, 3)C₁₋₄ alkyl, 4) C₃₋₇ cycloalkyl, 5) CF₃, 6) OCF₃, 7) C₁₋₄ alkoxy, and 8)cyano; R¹² is a 5-membered heteroaryl ring having 2, 3, or 4heteroatoms, provided that at least 1 heteroatom is N, and at most 1 ofthe heteroatoms is S, said ring being unsubstituted or substituted, atany one ring atom, with CH₃.
 2. A compound of claim 1, orpharmaceutically acceptable salt thereof, wherein R¹ is hydrogen, Cl, orCH₃.
 3. A compound of claim 2, or pharmaceutically acceptable saltthereof, wherein A is selected from the group consisting of


4. A compound of claim 3, or pharmaceutically acceptable salt thereof,wherein A is selected from the group consisting of

Z is selected from the group consisting of —CF₂CH₂—,—CH₂CH(CH₂N(CH₃)₂)—, —CH₂SO₂—, and —CH₂NH(C₂)₃—; X is N or CH; R¹ ishydrogen, Cl, or CH₃; and R² is selected from the group consisting of


5. A compound of claim 4, or pharmaceutically acceptable salt thereof,selected from the group consisting of


6. A composition for inhibiting thrombus formation in blood comprising acompound of claim 1 and a pharmaceutically acceptable carrier.
 7. Amethod for inhibiting thrombin in blood comprising adding to the blood acomposition of claim
 6. 8. A method for inhibiting formation of bloodplatelet aggregates in blood comprising adding to the blood acomposition of claim
 6. 9. A method for inhibiting thrombus formation inblood comprising adding to the blood a composition of claim
 6. 10. Theuse of a compound of claim 1, or a pharmaceutically acceptable saltthereof, in the manufacture of a medicament for inhibiting thrombin,inhibiting thrombus formation, treating thrombus formation, orpreventing thrombus formation in a mammal.
 11. A method for treating orpreventing venous thromboembolism and pulmonary embolism in a mammalcomprising administering to the mammal a composition of claim
 6. 12. Amethod for treating or preventing deep vein thrombosis in a mammalcomprising administering to the mammal a composition of claim
 6. 13. Amethod for treating or preventing thromboembolic stroke in humans andother mammals comprising administering to the mammal a composition ofclaim 6.